Method of checking a load circuit in a technical installation

Abstract

This invention relates to a method for inspecting load circuits of a control system in a facility, the control system comprising at least two load circuits having at least one load unit, a control unit (SE), and a clock-controlled power supply (SV). The power supply (SV) provides a supply voltage or supply current to the at least two load circuits via at least two output channels (A1-A8). The output channels (A1-A8) are controlled by control signals from the control unit (SE). First, a reference value for current or voltage is determined (101) for each predetermined facility state, wherein in the predetermined facility state, at least one output channel (A1-A8) is turned on and a predetermined voltage value for the supply voltage or a predetermined current value for the supply current is provided to each associated load circuit. The reference value determined for the predetermined facility state is stored (102). Then, during the self-test phase, for each pre-given facility state, the current value at each pre-given voltage value of the supply voltage or the current voltage value at each pre-given current value of the supply current is measured (103) on at least one activated output channel (A1-A8), and (104) it is checked (104) whether the respective currently measured values ​​deviate from a pre-given tolerance range when compared with their respective stored reference values ​​in one of the pre-given facility states. If the deviation from the tolerance range is found in a facility state, the corresponding associated load circuit is displayed (105).

Description

Technical Field

[0001] This invention generally relates to the field of electrical engineering, and more particularly to the field of power electronics and power electronic circuits. Specifically, this invention relates to a method for inspecting load circuits in a control system of a technical facility. The control system includes at least two load circuits, at least one control unit, and a clock-controlled power supply. The at least two load circuits, each having at least one load unit (e.g., sensor, actuator, relay, contactor, solenoid valve, servo motor, etc.), are supplied with a supply voltage and / or supply current by the clock-controlled power supply. For this purpose, the at least two load circuits are connected to at least two output channels, which are formed either by at least two direct output terminals of the power supply or by two externally connected and individually switchable output branches. To operate the at least two output channels, control signals are provided by the control unit. Background Technology

[0002] Complex machines and / or facilities are now used in many fields, such as industrial production and manufacturing, energy generation and distribution, automation technology, building management, etc. In this context, a facility should be understood as an organized combination of spatially related components (e.g., machines, equipment, and / or devices) that are interconnected in terms of function, control technology, and / or safety technology. Such technical facilities, such as production facilities, manufacturing facilities, energy generation and distribution facilities, etc., or their components, are becoming increasingly complex. Therefore, to operate technical facilities and complex machines effectively, control systems are typically used where sensor units or measuring units measure operating or process parameter values ​​of the facility or machine, and actuator units or load units (e.g., contactors, solenoid valves, optical or audible warning signals, motor units, display units, etc.) based on the measured operating or process parameter values ​​to, for example, change the operating or process parameters. The control system should enable the operation of the machine or facility to be as independent as possible and without human intervention.

[0003] To evaluate measurements from sensor or measuring units and to control actuator units (such as servo motors, warning signals, display units, etc.), control systems typically have control units. Control units can also, for example, connect or disconnect different load units, such as contactors or solenoid valves actuated by electromagnets, according to process requirements. Control units can be, for example, so-called programmable logic controllers (PLCs) or SPSs, microcontrollers, or industrial PCs.

[0004] Furthermore, such a control system also has at least one clock-controlled power supply (e.g., a switching power supply) that converts an unstable input voltage—mostly AC—into a constant output voltage—mostly DC (e.g., 24 volts)—to power the load units of the control system. Such a power supply (e.g., Siemens' SITOP PSU8600) may, for example, have at least two or more outputs for direct connection to the load circuit, wherein these outputs serve as output channels and can be manipulated by control signals from the control unit. Alternatively, a clock-controlled power supply can be used, and components (e.g., switchable fuse units, etc.) can be connected to the clock-controlled power supply, for example, via its outputs. This component then provides, for example, at least two individually switchable output branches as output channels. A load circuit having at least one load or load unit, or a set of load units, can be connected to each output channel. A supply voltage (e.g., 24 volts) and / or supply current, provided by the power supply, is then provided to the load or load circuit via the corresponding output channel. In order to control the output channel—that is, to connect or disconnect the voltage and / or current supply to the load circuit—the control unit may provide a control signal to, for example, the power supply, or the control unit may control the output channel and affect the supply voltage or supply current in the output channel (i.e., the supply voltage or supply current provided to the respective connected load circuits).

[0005] When a power supply has at least two output channels, the voltage and current can be set and monitored individually for each output channel. Thus, for example, the corresponding supply current or load current can be measured and monitored at each output channel, or alternatively, the voltage of the load circuits connected separately can also be measured and monitored. This allows, for example, the current consumption in the corresponding load circuit or the current voltage to be determined, where the current consumption or voltage in the corresponding load circuit can be changed by control and switching operations performed by the control unit of the control system. That is, the corresponding current consumption in the corresponding load circuit may be changed by connecting and disconnecting load units (e.g., contactors or solenoid valves) according to process technology requirements in the facility or machine.

[0006] After installation, expansion, or when commissioning complex machines or facilities, error checking is a crucial aspect of ensuring frictionless and safe operation. Timely identification of so-called wiring errors (i.e., errors occurring when connecting one or more load units to the load circuit or power supply output channel) in facilities or facility control systems is particularly important to ensure correct processes are implemented in the facility or machine and to protect load units (especially sensor units and / or actuator units) from damage or destruction.

[0007] The common method used to date for checking wiring is, for example, to perform so-called "wiring tests" or "continuity tests" using a continuity checker, either before commissioning the facility or during the testing phase. A continuity checker is an electrical inspection device that uses optical or acoustic signals to indicate whether an electrical connection exists between two points. For example, a continuity checker can be used to check the individual connections (mostly manually) between the power supply output path and the load units in the load circuit of a machine or facility's control system for correct wiring. However, this method is not only very time-consuming but also error-prone, especially in complex machines and / or facilities with multiple control system load circuits.

[0008] Another possibility for checking whether the wiring of a facility or machine's control system has been performed correctly is, for example, using an automated connection tester. This tester checks the connections by inspecting the series terminals in the switch cabinet of the facility or control system, for example, by checking the comb contacts, and then performing a pre-defined check against the facility's circuit diagram. However, such connection testers are relatively expensive to purchase and require, for example, dedicated inspection procedures that must be compatible with the facility or machine. In particular, the corresponding inspection procedures for the connection tester are almost impossible to reuse, or must be painstakingly adapted, for example, in the event of expansions or modifications to the facility or machine. Furthermore, while the connection tester checks the connections in the facility, it does not check the functionality of the connected facility components.

[0009] However, wiring errors can also be tracked during or after facility or machine commissioning. During commissioning, one load circuit of the control system can be activated, for example, after another load circuit, and the functionality of each load unit connected via that load circuit can be checked. However, this check is performed when the corresponding load circuit already has a supply voltage based on operation, and the corresponding load circuit is mostly protected only based on operation. Therefore, if there is incorrect wiring in the connected load units (e.g., sensor units or actuator units), these units may be damaged or destroyed. Furthermore, identifying the correctness of load units used in the facility or the facility's control system in this way, for example, in the case of incorrect signals or facility malfunctions (i.e., in the case of installing the wrong type of proximity switch or, for example, in the case of a sensor being assigned to the wrong load circuit), requires considerable effort.

[0010] Furthermore, for example, the REX system from ETA Elektrotechnische Apparate GmbH discloses a current distribution and safety system for centralized monitoring of modularly constructed facilities with distributed architecture. This system includes at least one power supply module for connection to a clock-controlled power source and at least one safety module, the safety module having one or two channels for connecting and protecting load circuits. For example, dynamic facility information and measurements (e.g., current voltage and current values ​​in load circuits connected via one or more safety modules, triggering reasons for the safety modules, etc.) can be determined via the power supply module and read by a higher-level control unit via a data connection. Additionally, nominal current and limit values ​​can be set for corresponding current values ​​in the load circuits, for example, within the safety module. Therefore, while such current distribution and safety systems can identify extreme defects, such as short circuits in load circuit wiring, short circuits in load circuits, or overcurrents (especially during continuous operation of the facility), it is difficult or almost impossible to identify wiring errors that may only result in small overcurrents or current drops compared to rated conditions, or the use of incorrect load units in load circuits (e.g., incorrect proximity switch types, incorrectly assigned sensors or actuators, on the power supply side and / or signal side, etc.), without user-specific, laborious manual troubleshooting or data analysis. Furthermore, the supply voltage range in the load circuit is limited to the typical operating voltage range of the corresponding components by at least one safety module, which is activated, for example, by operating voltage monitoring starting from approximately 16 volts. Additionally, the system may lead to increased complexity and cost, for example, during facility planning and maintenance, due to its modular construction.

[0011] Document EP 2 313 952 B1 discloses an electrical facility and a method for operating the facility, wherein the facility includes a power supply circuit for an appliance having at least one fixed wiring connection, the appliance being protected by means of a protective device. In this document, a control unit determines and stores a maximum current measurement value for each observation time interval to derive a limit value for adapting trigger parameters. Although the electrical facility and related methods known from document EP 2 313 952 B1 can be used to ensure that unidentified excessively high disconnection values ​​of the protective device are adapted accordingly during initial commissioning and / or during continuous operation, thereby improving the failure safety of the facility, it is impossible to identify whether at least one appliance or related load circuit is correctly wired.

[0012] Document DE 10 2018 114 094 B3 also discloses an output module for industrial control and a method for performing industrial control. In this document, the current current and voltage values ​​of the connected load are detected by a detection unit and processed in a calculation unit by means of an application to determine the physical state related to the load (e.g., load temperature, short circuit identification, cable breakage identification and / or winding short circuit identification, wear identification). For this purpose, an application is selected from a set of applications and loaded by means of a program memory. The evaluation results are transmitted to a control unit, a higher-level controller, and / or an external data memory. In the output module for industrial control and the method for performing industrial control disclosed in document DE 10 2018 114 094 B3, although defects such as short circuits, cable breaks, overheating, and wear on loads (especially valve coils, valve piezoelectric actuators, etc.) can be identified during the continuous operation of the facility, provided that the corresponding application can be used to evaluate the currently detected current and voltage values, it is difficult or almost impossible to identify wiring errors that may only cause a small overcurrent or current drop compared to the rated state, or the use of incorrect load units in the load circuit (e.g., incorrect proximity switch type, incorrectly assigned sensor or actuator, on the power supply side and / or signal side, etc.) without the user or by implementing the corresponding application specifically and laboriously manually searching for faults or analyzing data before commissioning the facility's self-test phase.

[0013] Furthermore, document EP 1 837 971 B1 discloses an overload protection method in which an overload state is generated for an output module used to control the load. In this document, the load current and load voltage of the load are monitored at sampling intervals and compared with a predetermined load current threshold. In this case, as long as the overload timer is running and the load current exceeds the load current threshold, a ramp-shaped load voltage value is generated for reference based on the starting load voltage and the magnitude of the predetermined load voltage increment. However, using this method also makes it difficult or even impossible to identify wiring errors in the facility. Summary of the Invention

[0014] Therefore, the objective of this invention is to describe a method for inspecting the load circuit of a facility or its control system, by which wiring errors and / or incorrect use of load units or misassigned signal units in the load circuit of the facility can be identified in a simple manner without the use of additional testing equipment or complex manual searches.

[0015] This task is accomplished by a method of the type described at the beginning, featuring the characteristics of the independent claims. Advantageous embodiments of the invention are described in the dependent claims.

[0016] According to the present invention, this task is solved by a method of the type described at the beginning for inspecting the load circuits of a control system of a facility, wherein the control system includes at least one control unit and a clock-controlled power supply in addition to at least two load circuits, each load circuit having at least one load unit or electrical appliance (e.g., contactor, solenoid valve, sensor unit, actuator unit, etc.). The at least two load circuits, each having at least one load unit, are supplied with supply voltage and / or supply current by the clock-controlled power supply via at least two output channels, wherein the at least two output channels may be formed by at least two direct output terminals of the power supply or by at least two output branches of components connected to the power supply. Furthermore, the output channels are also controlled by means of control signals from the control unit. In this case, the method according to the present invention includes at least the following steps:

[0017] - Determine a reference current value at a predetermined voltage value of the supply voltage or a reference voltage value at a predetermined current value of the supply current for each predetermined facility state, wherein in the predetermined facility state, at least one output channel is turned on and each associated load circuit of the control system is provided with the predetermined voltage value by the supply voltage or the predetermined current value by the supply current;

[0018] - Store the reference current value or the reference voltage value determined for the given facility state;

[0019] - During the self-test phase, for each current pre-given facility state, measure the current current value at each pre-given voltage value of the supply voltage or the current voltage value at each pre-given current value of the supply current on at least one on output channel.

[0020] - Check whether, in one of the pre-given facility states, the currently measured current value of each when the supply voltage is at least one pre-given voltage value is compared with the corresponding stored reference current value, deviates from the pre-given tolerance range, or whether the currently measured voltage value of each when the supply current is at least one pre-given current value is compared with the corresponding stored reference voltage value, deviates from the pre-given tolerance range.

[0021] - And if it is determined that the load circuit deviates from a predetermined tolerance range at at least one predetermined voltage value of the supply voltage or at at least one predetermined current value of the supply current in one of the predetermined facility states, the associated load circuit is displayed.

[0022] The main aspect of the solution proposed according to the invention is that it is therefore possible to perform very accurate and detailed measurements in the load circuits of a facility or complex machine or the control system of such facility or machine, and to evaluate the wiring and correctness of the load units connected to the corresponding load circuits, in a simple manner and without the use of testing equipment (e.g., continuity testers, connection testers, etc.). In other words, hidden wiring errors can be easily and readily discovered in a simple manner using the method according to the invention, without the need for, for example, manual searching or detailed data analysis performed by the user.

[0023] Wiring errors in the control system of the facility or machine may result in varying current consumption and thus varying load current in the corresponding load circuit, or voltage variations in the case of a pre-given or injected current. Similarly, it may have an effect in any load circuit where, for example, a load unit has been incorrectly connected. For instance, incorrect wiring of a load unit (e.g., a sensor, actuator, etc.) may result in lower current consumption than the determined reference current value in the load circuit assigned according to the circuit diagram, and higher current consumption than the determined reference current value in any load circuit where the load unit has been incorrectly connected.

[0024] In the method according to the invention, a predetermined facility state is generated during a self-test phase or during a test run of the facility or machine. Reference current or voltage values ​​have been determined for these facility states and stored as comparison values. The facility state describes the operating state of the facility or machine and can be generated, for example, via a control unit by correspondingly manipulating (i.e., turning on and off) output channels. That is, in the predetermined facility state, at least one load circuit is activated. At least one associated load unit of the load circuit is supplied with a supply voltage or supply current by a power source via a corresponding output channel, wherein the supply voltage is a predetermined voltage value or a supply current can be injected. Then, on at least one output channel activated in the current predetermined facility state, the current value of the load current in each associated load circuit is measured in a targeted manner for each predetermined voltage value of the supply voltage. By comparing the currently measured current value of the corresponding facility state with the corresponding reference current value, the correct wiring of the load circuit or at least one load unit can be inferred, and if necessary, the correct or planned functionality of at least one load unit can be inferred. Alternatively, the current voltage value can be determined in a targeted manner on at least one output channel connected in the current pre-given facility state for each pre-given current value or injected current value of the supply current in the corresponding load circuit. In this case, the currently measured voltage value of the corresponding facility state is then compared with the corresponding reference voltage value at each pre-given, injected current value of the supply current, and the wiring of the corresponding load circuit is inferred from the comparison. Thus, it is very easy, fast, and, if necessary, automatic (e.g., in the case of running a pre-given facility state in the form of a test procedure) to identify, for example, incorrect wiring and / or incorrectly inserted or installed load units in the load circuit.

[0025] According to an advantageous improvement of the method of the invention, for each pre-given facility state, a reference voltage value for any output channel shut down in each pre-given facility state is also determined and stored, and thus a reference voltage value for any load circuit disconnected in each pre-given facility state is determined and stored. Furthermore, during a self-test phase, current voltage values ​​are measured for the output channels shut down and the load circuits disconnected in each current facility state, and then compared with the corresponding reference voltage values ​​in the respective facility state. If the voltage value measured in the respective facility state deviates from a pre-given tolerance range when compared with the corresponding reference voltage value, the corresponding load circuit is identified. The correctness of wiring in a facility or machine or associated control system can also be easily assessed and checked by measuring the voltage on the shut-down or disconnected load circuits. Thus, for example, the voltage value measured on a shut-down output channel or output branch in a pre-given facility state can indicate incorrect wiring in the corresponding load circuit.

[0026] Furthermore, it may be advantageous to determine and store reference current values ​​for at least any output channels that are shut down in each pre-given facility state. Then, during the self-test phase, the current value for any output channel shut down in the corresponding facility state is measured and compared to the corresponding reference value. The corresponding load circuits that deviate from a pre-given tolerance range when compared to their respective stored reference current values ​​are then displayed. The current in the load circuits shut down in the corresponding facility state can also be additionally used to identify incorrect wiring or to assess the correct functioning of the corresponding load circuits or the control system of the facility or machine.

[0027] Ideally, for example during the planning and development phase of the facility or machine, reference current and voltage values ​​for the corresponding facility status can be determined by means of a reference facility, such as at the manufacturer. Therefore, when commissioning similar types of facilities or machines (e.g., a series of facilities / machines) at the corresponding usage locations, the reference current and, if necessary, reference voltage values ​​can be used to check whether the load circuits are correctly wired and whether the correct load units are installed at the planned locations or in the planned load circuits.

[0028] Alternatively or additionally, the reference current and reference voltage values ​​for the corresponding facility status can be determined during the commissioning phase of the facility to be inspected (e.g., during test commissioning at the manufacturer's facility, etc.) or derived from current and voltage values ​​continuously measured on the corresponding output channels for different facility statuses, for example, during the continuous operation of the facility or machine. That is, ideally, the reference values ​​are derived from earlier measurements taken under different facility statuses (e.g., during ongoing operation, commissioning at the manufacturer's facility, or during commissioning at the user's facility). This is particularly advantageous when the facility or machine is, for example, partially disassembled, transported, and reinstalled. Then, in the case of recommissioning or reconnection, the correct wiring of the load circuitry of the facility or machine control system or the correct functioning of the load circuitry can be checked very easily.

[0029] A further advantageous improvement to the method according to the invention specifies that, for each pre-given facility status, a reference value for a parameter and / or signal is detected and stored at the input of the control unit, and during a self-test phase, the current value of the parameter and / or signal at the input of the control unit is queried for each pre-given facility status and compared with the corresponding reference value. If the comparison between the current value of the parameter and / or signal and its corresponding stored reference value indicates a deviation from a pre-given tolerance range, the corresponding load circuit can be displayed. Such parameter and / or signal values ​​can be, for example, temperature sensor values, proximity switch stationary signals, speed sensor values, steam pressure values, functional signals, etc. This makes it particularly easy to determine wiring errors in the facility or machine.

[0030] Advantageously, a pre-defined tolerance range can be adapted for comparison between the currently measured current and / or voltage values ​​and the corresponding reference current and / or reference voltage values. The configurability of this tolerance range ideally compensates for fluctuations during current and / or voltage measurements or for slight drifts, thus avoiding, for example, unnecessary alarms. By periodically performing the method according to the invention, typical fluctuations in the load circuitry of a facility or machine can be identified, for example, and the tolerance range can be adapted accordingly, to avoid, for example, spurious errors caused by selecting the tolerance range too narrow or to avoid ignoring errors caused by selecting the tolerance range too wide.

[0031] The pre-defined tolerance range can be expressed, for example, as a percentage or as an absolute range. A combination of both is also possible. Furthermore, tolerance ranges can be pre-defined for all load circuits to be inspected, or tolerance ranges specific to the respective load circuits can be pre-defined.

[0032] Ideally, the corresponding facility status, and thus each on and off output channel (i.e., the on or off output terminal of the power supply or each on and off output branch of an external connection), as well as the voltage value of the supply voltage or the current value of the supply current of the corresponding output channel, are pre-defined by the control unit. At least a plurality of load units can be manipulated (i.e., activated and deactivated in a targeted manner) by the control unit, which may be implemented, for example, as a programmable logic controller (SPS), microcontroller, or industrial PC. Defined, pre-defined facility statuses can thus be easily created by the control unit, in which, for example, individual load units or load circuits are active, while the remaining load units of the control system are deactivated. Furthermore, the control unit may also have a data connection to the power supply. Control signals for setting the pre-defined facility status can thus be forwarded by the control unit to a clock-controlled power supply. The clock-controlled power supply then, for example, turns on and off the corresponding output channel or output branch and thus the connected load circuit and load unit, according to the pre-defined facility status. Furthermore, under the corresponding facility conditions, the voltage value of the power supply voltage or the current value of the power supply current can be preset by the control unit for the power supply or set on the externally connected output branch.

[0033] Advantageously, a predefined waiting time is set between changing a predefined voltage value of the supply voltage or a predetermined current value of the supply current in each predefined facility state and determining the reference current value or the reference voltage value (e.g., determining the current measured current value for the predefined voltage value of the supply voltage or the current measured voltage value for the predefined current value of the supply current). This allows for the simple, for example, minimizing, the influence of current consumption fluctuations or voltage fluctuations on the measurement of the corresponding reference value or current measured value (current or voltage), which are caused by the corresponding load unit in the load circuit by connecting the supply voltage to the corresponding load circuit (i.e., turning on the corresponding output channel) or by changing the voltage value of the supply voltage or by changing the current value of the supply current. For example, a predefined waiting time can be selected such that a stable current value has been reached for measuring the current value in the corresponding load circuit, for example, with relatively low fluctuations (e.g., a deviation of 3% per second). For example, a predefined value for the predefined waiting time for the corresponding load circuit or corresponding load unit can be determined during the determination of the reference value of the current or voltage, and then used in the self-test phase. Therefore, for example, the latency in the load cell or load circuit can be reduced to a minimum without a significant settling time. In cases where the load cell has a relatively large settling time, a safety margin can also be set for a pre-defined latency to obtain stable measurements.

[0034] Furthermore, it is conceivable to form the reference current value and / or the current current measurement as the average of multiple current measurements taken over a pre-given integration time (e.g., 0.1 seconds, 10 seconds, etc.), or to implement other types of mathematical filtering to reduce the impact of current consumption fluctuations in the load circuit—especially in the case of supply voltage variations—or noise when determining the current measurement. Additionally, when the reference current value is first recorded, a steady-state process during changes in the supply voltage (i.e., during the switching on of the supply voltage in the corresponding load circuit or the change of the supply voltage value) can be jointly determined. The time variation or steady-state process can be characterized, for example, based on a time series or storage of the reference current value, thereby, for example, depicting the time-varying reference current of the steady-state process. A similar process (e.g., mathematical filtering) can also be conceivable when determining the reference voltage value (e.g., the current measurement of the voltage) to reduce or eliminate the steady-state process, for example, when connecting or changing the supply current.

[0035] Furthermore, it is advantageous to increase the supply voltage from the initial supply voltage (e.g., 0 volts) to a predetermined nominal voltage (e.g., 28 volts) or to the operating limit of at least one load circuit unit connected to the corresponding load circuit in predetermined voltage steps. By increasing the supply voltage in predetermined voltage steps (e.g., in 2-volt increments), it is possible, for example, to measure specific current values ​​of the load circuit and / or typical current values ​​of the corresponding load unit, which provide additional support in detecting wiring errors and any faults. Thus, for example, a small sensor can have a linear regulator with internal electronics through which the sensor is only turned on starting from a specific supply voltage (e.g., 5 volts or 12 volts), and the internal electronics, for example, maintain a constant current consumption until the specific voltage (e.g., 28 volts). Higher power consumers (e.g., control units, etc.) have, for example, buck converters to generate an internal auxiliary voltage, and, for example, reduce the current as the supply voltage increases. For example, a contactor as a load unit has a current consumption that increases linearly with increasing supply voltage. DC motors can, for example, have very low resistance at low voltages and consume high current, which can, for example, rise or even fall in a flat curve as rotational motion begins.

[0036] As an alternative to gradually or progressively increasing the supply voltage on at least each activated output channel of the power supply, it is also advantageous to increase the predetermined voltage value of the supply voltage from the initial supply voltage (e.g., 0 volts) to a predetermined nominal voltage (e.g., 28 volts) or to the operating limit of at least one load circuit unit connected to the corresponding load circuit in the form of a linear voltage ramp with a predetermined slope. Furthermore, in this case, the rate of increase of the supply voltage can also be predetermined. The current value in each of the at least one activated load circuits of the corresponding facility state is then measured synchronously with the increase of the supply voltage. To, for example, speed up the operation time of the method, different rates of increase can be selected, for example, according to one or more corresponding load units in the load circuit for different supply voltage ranges. For example, if it is known that the appliances or load units in the load circuit are only turned on in the voltage range of 14 to 16 volts, the voltage range up to 14 volts can be operated, for example, more quickly (i.e., with a higher rate of increase). Then, for voltage ranges starting from 14 volts, a lower rate of rise is selected to determine, for example, the actual on-state voltage of the load unit, the corresponding current measurement, and to identify possible wiring errors.

[0037] The determined reference current value and, if necessary, the determined reference voltage value can be stored in the control unit of the facility or machine control system. Therefore, the method according to the invention can be executed by the control unit, for example, in the form of a test procedure. In addition to a pre-defined facility state to be operated, the control unit can also check, for example, whether a sensor unit installed in a load circuit returns a measured value when the corresponding load circuit is activated. Such measured values ​​or sensor signals can be stored appended to the reference current value and / or reference voltage value, providing additional possibilities for checking correct wiring or correct operation during the self-test phase of the facility or machine, particularly the correct wiring or correct operation of sensor units in the control system.

[0038] Alternatively or additionally, the determined reference current value and, if necessary, the determined reference voltage value can be transmitted to the evaluation and / or data processing unit—mostly designed as a central unit or a higher-level unit—and stored there. Therefore, the reference values ​​can be readily used to inspect various facilities or machines of the same structural type.

[0039] Furthermore, it is advantageous to select pre-given facility states via the evaluation and / or data processing unit. This allows for the creation, for example, a test program for a self-test phase of a facility or machine, which runs, for example, during user commissioning of the facility or machine. Therefore, during selection, facility states that have proven useless for inspection due to repeated runs of the test program can be removed or not selected. In this way, the inspection process can be expedited, as only relevant facility states can be selected, for example. Additionally, a list of facility states (e.g., pump or valve activation) may already be pre-given for the selection, which, for example, does not contain useless, hazardous, or unwanted facility states, or ideally, these facility states can be excluded during selection.

[0040] Then, the current value currently measured for the corresponding facility status, and the voltage value measured if necessary, can also be forwarded to the evaluation and / or data processing unit and stored there. Storing the current measurements makes it very easy to expand the possibilities for analysis and evaluation. Furthermore, the measurement results can be easily displayed graphically, or the temporal evolution of the facility or machine can be evaluated. In this way, for example, it is possible to identify in a timely manner any impending fault in the load circuit or any changes that may lead to the failure of the facility or machine. Attached Figure Description

[0041] The invention is explained below by way of example with reference to the accompanying drawings.

[0042] Figure 1 A schematic and exemplary structure of a control system for performing the method for inspecting a load circuit according to the present invention is shown.

[0043] Figure 2 An exemplary flow diagram of a method for inspecting the load circuit of a control system in a facility, according to the present invention, is shown. Detailed Implementation

[0044] Figure 1A control system for a technical facility or complex machine is illustrated schematically by way of example. In this case, the exemplary control system includes at least one control unit SE, which may be implemented, for example, as a programmable logic controller (PLC) or simply an SPS. Alternatively, a microcontroller or industrial PC may also be used as the control unit SE. For example, to manipulate load units, such as to switch switch units S1, ..., S4, the control unit SE has digital outputs O1, ..., O4. Alternatively, switch units S1, ..., S4 may also be part of the output components of the control unit SE, particularly digital output components with a PLC or SPS. Alternatively or additionally, the control unit SE may also have analog outputs, such as actuator units or switch units that can be connected to said analog outputs. Figure 1 For simplicity, the analog outputs of the control unit SE are not explicitly shown. The digital outputs O1, ..., O4 and the analog outputs provide the control unit SE with the possibility of manipulating the facility or machine, particularly during operation, and thereby adjusting or creating the operating state of the facility or machine. Furthermore, the control unit SE exemplarily has digital inputs I1, I2, via which signals can be received, for example, from load units—specifically, sensor units DS, AS. The signals received at inputs I1, I2 can inform the control unit SE of the current situation in the facility or machine, and can, for example, trigger specific control and regulation processes. The control unit SE may also have analog inputs for connecting to and querying sensor units.

[0045] The exemplary control system also includes, for example, a clock-controlled power supply SV, which is connected to the supply voltage U via an input side IN. AC (For example, three-phase AC voltage). The power supply SV has, for example, eight output terminals, and therefore eight output channels A1, ..., A8. The load circuit of the control system is directly connected to these output channels, and the load circuit of the control system of the facility or machine is supplied with supply voltage (e.g., 24V DC voltage) or supply current by the power supply SV via these output channels. The power supply SV can, for example, provide the following possibilities, such as the SITOP PSU8600: the ability to individually set and monitor the supply voltage value supplied to the load circuit for each output channel A1, ..., A8, as well as to individually set and monitor the current.

[0046] Alternatively, the control system may also have a power supply SV, to which an external component (e.g., an externally switchable fuse unit) with at least two output branches is connected, and these at least two output branches form at least two output channels A1, ..., A8 for the power supply SV. These output branches or output channels A1, ..., A8 may be individually switched, and the voltage and current supplied to the load circuits can be individually set and monitored. Current or voltage is then supplied to the respective load circuits or load units belonging to these load circuits via output channels A1, ..., A8.

[0047] exist Figure 1 In the control system illustrated by way of example, a supply voltage is pre-set for each associated output channel A1, ..., A8 to the corresponding load circuit, thereby forming the variables to be measured for a reference value and a current measurement value for the corresponding facility state by the corresponding current consumed by the at least one load unit in the corresponding load circuit. Alternatively, the power supply SV or at least one output channel A1, ..., A8 of the power supply SV can, for example, operate as a current source. In this case, a supply current or load current is pre-set or injected for the corresponding output channel A1, ..., A8 as a pre-set value. The voltage for the reference value is then determined or measured as the current measurement value for the corresponding facility state, wherein the voltage can be set according to the impedance of the corresponding load unit in the load circuit and measured with higher accuracy if necessary, or the voltage can be more easily measured when the load has a capacitive element or has a capacitor.

[0048] Furthermore, the power supply (SV) and control unit (SE) of the control system can have an interface module (DV) via which a bidirectional data connection can be established for transmitting control signals and data information. For example, Profinet (Process Field Network)—an open industrial Ethernet standard from the PROFIBUS user organization—can be used for this data connection.

[0049] In order to provide voltage to the control unit SE, such as Figure 1 As shown in the example, it can be set to Figure 1 A dedicated power supply is not shown. Alternatively, the corresponding supply voltage can be provided to the control unit SE by a power supply SV controlled by the control system's clock. For this purpose, the control unit SE can, for example, be connected to the first output channel A1 of the power supply SV.

[0050] The load circuits of the control system of the facility or machine are connected to output channels A1, ..., A8. Each load circuit may have at least one load unit, such as at least one actuator unit, switch unit, or sensor unit. Figure 1In the control system illustrated by way of example, switching units S1, S2, S3, S4 and associated load resistors R1, R2, R3, R4 are connected, for example, to the first output channel A1 and the second output channel A2. These switching units S1, S2, S3, S4 and the associated load resistors R1, R2, R3, R4 can be switched on or off by means of the corresponding digital outputs O1, O2, O3, O4 of the control unit SE. Other actuator units or switching units S5, S6 (e.g., contactors, solenoid valves, etc.), also serving as load units, such as modules for switching on or off electric valves, motors, or drive control, are connected to the third and fourth output channels A3, A4. These actuator units and switching units S5, S6 can be controlled, for example, by the control unit SE of the control system or another control unit.

[0051] For example, the optical signal LS used to operate the fan unit and the motor M are connected to the fifth output channel A5 of the power supply SV. For example, an additional load resistor R5 is connected to the sixth output channel A6 of the power supply SV. In this case, for example, the motor M or the fan unit is incorrectly not connected to ground from the fifth output channel A5—as shown by the dashed line—but is connected to the sixth output channel A6 due to a first wiring error VF1 (e.g., during the construction of the facility or machine). In this case, the first wiring error VF1 is shown as a dotted line.

[0052] A second exemplary wiring error VF2 is illustrated in the wiring of the seventh and eighth output channels A7 and A8 of the power supply SV. The seventh and eighth output channels A7 and A8 are connected, for example, to sensor units DS and AS as load units, which, for example, provide input signals to the corresponding digital inputs I1 and I2 of the control unit SE. With correct wiring—again shown by dashed lines—for example, the pressure sensor DS would be connected to the seventh output channel A7, which reports the input signal to the digital input I2 of the control unit SE as soon as a threshold is reached, and the acoustic signal unit AS would be connected to the eighth output channel A8, which outputs a function signal to the digital input I1 of the control unit SE during operation. Due to the second wiring error VF2—as shown by the dashed lines—the connections of the two sensor units DS and AS have been interchanged. Therefore, the acoustic signal unit AS now receives its corresponding supply voltage via the seventh output channel A7, while the pressure sensor DS receives its corresponding supply voltage via the eighth output channel A8. However, the corresponding signal outputs of the pressure sensor DS and the acoustic signal unit AS are connected to the correct digital inputs I1 and I2 of the control unit SE, respectively.

[0053] Figure 2The flow of a method according to the present invention for inspecting load circuits in a facility or a control system of a facility is illustrated by way of example, the facility being such as Figure 1 As shown in the example.

[0054] When performing the method according to the invention, particularly in the reference value determination step 101 and the measurement step 103, a pre-given facility state is determined. The reference value determination step 101 is used to determine reference current values ​​and, if necessary, reference voltage values ​​in the corresponding output channels A1, ..., A8 of the power supply SV. The measurement step 103 determines the current current values ​​and, if necessary, the current voltage values ​​in the corresponding output channels A1, ..., A8 of the power supply SV. These facility states are generated, for example, by control commands from the control unit SE, through which the output channels A1, ..., A8 of the power supply SV are turned on or off, for example, by the power supply SV itself, and, if necessary, the output terminals O1, ..., O4 of the control unit SE are activated or deactivated. Additionally, for the pre-given facility state, the current parameter values ​​or signal values ​​of the sensor units DS, AS can also be queried, for example, from the input terminals I1, I2 of the control unit SE.

[0055] In this context, the operating condition of the facility or machine is considered as a pre-defined facility state, defined or generated by the control unit SE and the activated load circuit (i.e., the load circuit supplied with power). That is, for a given facility state, at least one output channel A1, ..., A8 of the power supply SV becomes active or switched on, and the associated load circuit is supplied with voltage by the power supply SV. Additionally, if the load circuit switched to the active state has load units S1, ..., S4 controlled by the control unit SE, the corresponding output terminals O1, ..., O4 of the control unit SE can be activated, or if the load circuit switched to the active state has sensor units DS, AS, the corresponding input terminals I1, I2 of the control unit can be queried. Such inputs (e.g., temperature values, speed values, steam pressure values, function signals, etc.) can be used, for example, to check the correct wiring of the load circuit—especially the sensor units DS, AS. Therefore, specific switching positions and parameters exist for the corresponding facility state, particularly in the control unit SE. In order to determine the reference values ​​and current measurements of current and voltage in the load circuit, ideally the following facility states are given in advance, in which, as long as the corresponding load circuit has load elements S1, ..., S4 controlled by the control unit SE, for example, only one output channel A1, ..., A8 and the control unit SE for example, only one output terminal O1, ..., O4 are activated at the same time.

[0056] Therefore, for technical facilities or machinery in Figure 1The control system exemplified herein, which should be checked using the method according to the invention, may, for example, define at least twelve functional facility states, and these facility states may be pre-defined, for example, in the form of a test procedure, if necessary. For these twelve functional facility states, one of the eight output channels A1, ..., A8 may be activated, for example, by a control command sent by the control unit SE via data connection DV to the power supply SV. Additionally, one of the digital outputs O1, ..., O4 of the control unit SE may be activated to turn on the associated switching units S1, ..., S4 when the corresponding first or second output channel A1, A2 of the power supply SV is turned on. That is, for the exemplary first facility state, the first output channel A1 is activated and the remaining output channels A2 to A8 remain closed. Then, for the exemplary second facility state, after activating the first output channel A1, the first digital output O1 of the control unit SE may be additionally activated to switch the first switching unit S1 in the load circuit connected to the first output channel A1 and turn on the associated load resistor R1. For the exemplary third facility state, for example, the first output channel A1 remains on and the remaining output channels A2, ..., A8 of the power supply SV remain closed. However, now the first digital output terminal O1 of the control unit SE is deactivated (i.e., the associated load resistor R1 is disconnected) and the second digital output terminal O2 of the control unit SE is activated, so as to switch the second switching unit S2 in the load circuit connected to the first output channel A1 and turn on the associated load resistor R2. For example, it can also be for Figure 1 The second output channel A2 of the power supply in the exemplary facility is pre-defined with a corresponding facility state. In the remaining facility states, for example, one of the power supply output channels A3 to A8 is turned on or activated to provide a power supply voltage to the associated load circuit.

[0057] To reduce testing time, multiple output channels A1, ..., A8 of the power supply SV and / or multiple output terminals O1, ..., O4 of the control unit SE can be activated simultaneously. For Figure 1 The control system of the facility or machine shown can, for example, combine the second and third facility states described above by simultaneously activating the first and second output terminals O1 and O2 of the control unit in addition to the first output channel A1 of the power supply SV, switching the associated switching elements S1 and S2 in the load circuit connected to the first output channel A1 of the power supply SV, and simultaneously turning on the associated load resistors R1 and R2. For example, the facility states can also be combined similarly for the second output channel A2 of the power supply SV.

[0058] In a real facility, significantly more facility states can be defined and used in accordance with the method according to the invention. However, useless, dangerous, or meaningless facility states (e.g., facility states that activate pumps or valves in an undesirable manner) can be excluded in this case. Furthermore, pre-defined facility states, or facility states deemed meaningful, can be combined in the form of a test procedure that can, for example, be adapted to the self-testing phase of a facility or machine put into operation by the user—that is, facility states can be selected and pre-defined in a facility-specific and / or user-specific manner.

[0059] To inspect the load circuit in the facility according to the method of the present invention, in the reference value determination step 101, a reference current value is determined for each predetermined facility state (that is, when at least one output channel A1, ..., A8 of the power supply SV is turned on) given a predetermined supply voltage value. Specifically, a predetermined facility state (e.g., a first facility state where the first output channel A1 of the power supply SV is turned on; a second facility state where the first output channel A1 is activated and the first digital output terminal O1 of the control unit SE is activated; etc.) is generated, for example, by means of the control unit SE. Then, for example, a predetermined voltage value for associating the supply voltage of the load circuit and an associated current value are set by the power supply SV at at least one turned-on (e.g., the first) output channel A1 of the power supply SV.

[0060] Alternatively, in reference value determination step 101, instead of the reference current value for each predetermined facility state (i.e., when at least one output channel A1, ..., A8 of the power supply SV is turned on), a reference voltage value can be determined based on a predetermined supply current value. That is, a predetermined facility state (e.g., a first facility state where the first output channel A1 of the power supply SV is turned on; a second facility state where the first output channel A1 is activated and the first digital output terminal O1 of the control unit SE is activated; etc.) is generated, for example, by means of the control unit SE. Then, a predetermined voltage value for the supply current for associating with the load circuit is injected, for example, by the power supply SV at at least one turned-on (e.g., the first) output channel A1 of the power supply SV, and the associated voltage value is determined.

[0061] Additionally, voltage values ​​can be determined as additional reference voltage values ​​and / or current values ​​can be determined as additional reference current values ​​on the remaining output channels A2, ..., A8 that are shut down under a pre-given facility state, and parameter values ​​and / or signal values ​​of sensor units DS, AS can be queried as reference values ​​applied to input terminals I1, I2 of control unit SE.

[0062] The reference current value can be obtained, for example, by means of a reference facility or reference machine, such as by the manufacturer during the development and testing phase (i.e., after a series of facilities or machines have been developed). Alternatively or additionally, for example in the case of a user-specific facility or machine, the reference current value can be determined during the initial commissioning of said facility or machine, or derived from the current values ​​measured on the respective output channels A1, ..., A8 for a predetermined facility state during ongoing operation. Similarly, if necessary, a reference voltage value for a predetermined facility state can also be determined on the reference facility or reference machine or during the initial commissioning of said facility or machine, or derived from the voltage values ​​continuously measured during operation.

[0063] In storage step 102, a reference current value determined for a predetermined facility state and a reference current value determined for a predetermined supply voltage value for the corresponding load circuit are stored. In this case, the reference current value may be stored, for example, in the control unit SE of the facility's control system or transmitted to the control unit SE of a similar type of facility or machine. Alternatively or additionally, the reference current value may also be transmitted to, for example, a centrally available evaluation and / or data processing unit and stored there. If a reference voltage value is alternatively determined for a predetermined supply current value in the corresponding load circuit for a predetermined facility state, or additionally determined for other reference voltage values ​​on closed output channels A1, ..., A8, these reference voltage values ​​may also be stored in the control unit SE. Alternatively or additionally, the reference voltage value may also be transmitted to the evaluation and / or data processing unit and stored there along with the corresponding reference current value. That is, in storage step 102, at least one reference current value for each predetermined supply voltage value in the corresponding load circuit or a reference voltage value for each predetermined supply current value in the corresponding load circuit is stored for each predetermined facility state.

[0064] Using measurement step 103, a self-test phase is initiated on the facility or machine to be inspected. This self-test phase can be run during commissioning—for example, after the transport and reinstallation or new installation of the corresponding facility or machine, or during a restart while the facility or machine is running. Then, in measurement step 103, the control unit SE selectively generates a pre-defined facility state, for example by means of commands sent to the power supply SV via data connection DV and, if necessary, by means of signals sent to load units S1, ..., S4 connected to the output of the control unit SE. The pre-defined facility state can be selected, for example, from a list of possible facility states or a list of facility states that are meaningful to the facility or machine. This list can be created, for example, before or during reference value determination step 101 and stored, for example, in the control unit SE or the evaluation and / or data processing unit.

[0065] Furthermore, in measurement step 103, for each predetermined facility state, a predetermined voltage value for the supply voltage is predetermined on at least one activated output channel A1, ..., A8 of the power supply, for example, predetermined via command from the control unit SE through the power supply SV. Then, for each predetermined voltage value of the supply voltage, the current value is measured and stored on at least one activated output channel A1, ..., A8 of the power supply SV. That is, for each predetermined facility state, the current current value is obtained for each predetermined voltage value of the supply voltage, and then the current current value can be evaluated relative to the corresponding reference current value.

[0066] To operate the supply voltage at a predetermined voltage value for each currently predetermined facility state in measurement step 103, the supply voltage can, for example, start from a starting supply voltage (e.g., 0 volts) and increase to a predetermined nominal voltage (e.g., 2 volts) in predetermined voltage steps (e.g., 24 or 28 volts). Alternatively, the supply voltage can also increase from the starting supply voltage (e.g., 0 volts) to the predetermined nominal voltage (e.g., 24 or 28 volts) in the form of a linear voltage ramp with a predetermined gradient or rate of increase, and the predetermined voltage value of the supply voltage can be operated in this manner. If the predetermined voltage value of the supply voltage on at least one activated output channel A1, ..., A8 of the power supply SV is changed incrementally or by means of a ramp-shaped increase to the next predetermined voltage value, a predetermined waiting time can be set between changing the voltage value of the supply voltage and measuring the current current value in at least one activated output channel A1, ..., A8 of the power supply SV. In this way, for example, current fluctuations caused by a stabilization process due to voltage changes are not measured together, but rather the current current value is measured as static or constant as possible. Furthermore, it can be specified that an average value of the measurements is formed over a pre-given integration time (e.g., 0.1 or 10 seconds), or other mathematical filtering is performed, to reduce current fluctuations and / or noise when determining the current current value. The filtering can also be performed on multiple current measurements executed in a predetermined order to determine measurements filtered at pre-given intervals (e.g., every 10 seconds) over a pre-given time period (e.g., 1 minute), thereby enabling the description of the stabilization process of the load unit or appliance.

[0067] To determine the reference value of current or voltage in reference value determination step 101, the same method described above for changing the pre-given voltage value of the supply voltage on at least one active output channel A1, ..., A8 under a pre-given facility state can be applied. In this case, a waiting time can be set between changing the supply voltage value and determining the reference current value, or between changing the supply current value and determining the reference voltage value, or a filtering method can be applied to reduce fluctuations and / or noise, for example, caused by the stabilization process. It should be noted that in this case, the same method is used in measurement step 103 to change the supply voltage value and reduce current fluctuations (e.g., waiting time, mathematical filtering, performing multiple measurements at pre-given intervals in a pre-given order during a pre-given time period, etc.).

[0068] Additionally, in measurement step 103, the current voltage values ​​on the output channels A1, ..., A8 of the power supply SV, respectively, which are closed under predetermined facility conditions, can also be measured. The current current values ​​on any of the output channels A1, ..., A8 of the power supply SV, respectively, which are closed under predetermined facility conditions, can also be measured. These currently measured voltage and current values ​​are also stored and can be used to evaluate and inspect the load circuitry of the facility or machine.

[0069] Alternatively, in measurement step 103, instead of the current current value, the current voltage value on at least one active output channel A1, ..., A8 can be measured for each predetermined facility state. To do this, for each predetermined facility state, a predetermined current value of the supply current is injected into at least one active output channel A1, ..., A8—for example, executed by the power supply SV via a command from the control unit SE. Then, for each predetermined current value of the supply current, the current voltage value is measured and stored on at least one active output channel A1, ..., A8 of the power supply SV. That is, for each predetermined facility state, the current voltage value is obtained for each predetermined current value of the supply current, and then the current voltage value can be evaluated relative to a corresponding reference voltage value. To determine the current voltage measurement, the same method described above can be applied to change the predetermined current value of the supply current on at least one active output channel A1, ..., A8 in each predetermined facility state, and corresponding filtering methods or waiting times can be applied to allow for stabilization and reduce noise.

[0070] The current or voltage values ​​currently measured on at least one active output channel A1, ..., A8 of the power supply SV, and, if necessary, the voltage values ​​measured on inactive output channels A1, ..., A8 of the power supply SV, can, for example, also be stored in the control unit SE, which then, for example, performs an evaluation. However, the measured current and voltage values ​​can also be forwarded to the evaluation and / or data processing unit and stored there. The evaluation is then, for example, also performed by the evaluation and / or data processing unit.

[0071] Then, in inspection step 104, for each pre-given facility state, the currently measured current value is compared with the corresponding reference value, which is determined by the corresponding pre-given voltage value of the supply voltage on at least one activated output channel A1, ..., A8 of power supply SV for each pre-given facility state. In this case, the reference current value determined in reference step 101 for each identical facility state and the corresponding voltage value for the supply voltage is used. In the comparison between the currently measured current value and the corresponding reference value, it is checked whether the supply voltage on at least one activated output channel A1, ..., A8 or in at least one activated load circuit of the inspected facility state exceeds a pre-given tolerance range. If the current voltage value is measured instead of the current current value in measurement step 103, then in inspection step 104, the current voltage value is compared with the corresponding reference voltage value determined in reference step 101, and it is checked whether it conforms to the pre-given tolerance range.

[0072] In this context, the pre-defined tolerance range can be described, for example, as a percentage or as an absolute range. In this case, tolerance ranges can be set for all load circuits to be inspected in the facility or machine. However, tolerance ranges can also be pre-defined individually, on a load circuit-specific basis, or for example, for load circuits of the same or similar design. Furthermore, if, for example, during operation of the method according to the invention or in multiple applications, it is identified that the pre-defined tolerance range is selected as being too narrow or too wide, the tolerance range can be adapted. By selecting, for example, a tolerance range that is too narrow, spurious errors may occur, for example, due to fluctuations in the load circuit and / or, for example, signs of aging in the load units. That is, errors may still be displayed in the load circuit even though the facility is functioning correctly. If the tolerance range is selected as too wide, for example, actual wiring errors and / or functional errors in the load units may be overlooked. The pre-defined tolerance range can be adapted, for example, based on current measurements stored in the load circuit at different times.

[0073] If, in inspection step 104, it is determined that, under the currently inspected pre-given facility state, the comparison between the currently measured current value and the corresponding reference current value does not meet the tolerance range when the supply voltage on at least one pre-given voltage value of at least one activated output channel A1, ..., A8 of power supply SV is at least at least a pre-given voltage value, then in display step 105, the load circuit connected to at least one activated output channel is displayed. The corresponding load circuit can be displayed, for example, by the control unit SE. For this purpose, a display unit (e.g., a monitor, a mobile display unit, etc.) assigned to the control unit SE can be used. This also applies to situations where voltage is measured instead of current for the corresponding facility state in each load circuit switched to the active state.

[0074] When inspection step 104 is performed on the evaluation and / or data processing unit, the corresponding load circuit suspected of having a wiring error due to the measured current value can be displayed in display step 105, for example, via the output unit of the evaluation and / or data processing unit. In this case, the measured value of current or voltage and / or the comparison with a reference current value or reference voltage value can be prepared graphically—for example, in the form of a table, curve, etc. Furthermore, in the case of evaluation by the evaluation and / or data processing unit, previously stored current or voltage measurements of the load circuit can also be graphically output and displayed on the output unit, for example, by comparing the load circuit with the currently measured current or voltage measurements of the load circuit.

[0075] If, in inspection step 104, it is determined by comparing each current measurement value with its corresponding reference value in the currently inspected pre-given facility state that there is no deviation (i.e., the absolute value or percentage exceeds or falls below) from the pre-given tolerance range, then the next pre-given facility state is inspected. This facility state is pre-given for the facility or machine to be inspected, and the current measurement value and reference value are available for this state. If, in another pre-given facility state, a deviation from the pre-given tolerance range, or for example, a tolerance range pre-given in a load circuit-specific manner, is determined by a corresponding comparison of the current measurement value with its corresponding reference value, then the corresponding load circuit can also be displayed in display step 105. If, in another pre-given facility state, a deviation from the tolerance range, or for example, a tolerance range pre-given in a load circuit-specific manner, is not exceeded by a corresponding comparison of the current measurement value with its corresponding reference value, then the method according to the invention is terminated using termination step 106. In termination step 106, for example, the output may be: No abnormality was identified in the inspected load circuit of the facility or machine.

[0076] Additionally, provided the measurement was performed in measurement step 103, the currently measured voltage values ​​on the output channels A1, ..., A8 of the power supply SV, which are closed in the corresponding facility state, can also be compared with the corresponding reference voltage values. If, in inspection step 104, a voltage value is determined, for example, on the output channels A1, ..., A8, which are closed for the given facility state to be inspected, that exceeds the reference voltage value (e.g., 0 volts) by more than a given tolerance range, this may also indicate an error in the wiring of the facility, machine, or associated control system. The corresponding load circuit can then be displayed again in display step 105.

[0077] In addition, during inspection step 104, the current values ​​currently measured on the output channels A1, ..., A8 of the power supply SV that are closed in the corresponding facility state can be considered in order to detect wiring errors and / or functional errors in the facility or load circuit.

[0078] exist Figure 1 In the facility or machine illustrated by way of example, during the operation of the self-test phase—which includes at least a measurement step 103, an inspection step 104, a display step 105, and a termination step 106—two exemplary wiring errors VF1 and VF2 are identified in a corresponding pre-given facility state. Thus, for example, in inspection step 104, in a pre-given facility state where at least the fifth output channel A5 of the power supply SV is turned on, it is determined that, for example, the currently measured current value and, if necessary, a comparison of the currently measured current value with a corresponding reference value, is outside a pre-given tolerance range. The comparison deviates from or exceeds the tolerance range, for example, in absolute or percentage terms, because, for example, the motor M or fan unit is incorrectly not directly grounded through the fifth output channel A5, but is instead connected to the sixth output channel A6 due to a first wiring error VF1 (e.g., during facility or machine construction), and when the fifth output channel A5 of the power supply SV is activated, current is also fed into the load circuit connected to the sixth output channel A6. In other words, in measurement step 103, for example, a current value deviating from (e.g., lower than) the corresponding reference current value is measured on the fifth output channel A5 of the power supply. This can be demonstrated by comparing it with the corresponding reference value, for example, by absolute value or percentage, exceeding a predetermined tolerance range. Furthermore, in measurement step 103, for example, a voltage or current value that would not be measured on the sixth (off) output channel A6 under correct wiring is measured. Then, in inspection step 104, it can be determined that one or more tolerance ranges have deviated from the facility state (i.e., at least the fifth output channel A5 of the power supply SV is activated), and in display step 105, the load circuit connected to the fifth output channel A5 of the power supply SV can be displayed as faulty.

[0079] Similarly, in the corresponding facility states—for example, a facility state where only the seventh output channel A7 of the power supply SV is activated, and a facility state where only the eighth output channel A8 of the power supply SV is activated—an additional second wiring error VF2 can be identified during the facility or machine's self-test phase, in which the connections of the two sensor units DS and AS have been interchanged. This wiring error or the corresponding load circuit can then be displayed in display step 105.

[0080] If the current values ​​measured in the activated facility states of the seventh and eighth output channels A7 and A8 have a slight difference from the corresponding reference current values, such that the comparison is within one or more pre-defined tolerances, then the incorrect load unit or sensor unit DS, AS is activated by the incorrect wiring of the second wiring error VF2. That is, when the pressure sensor DS should actually be activated, the functional signal emitted by the acoustic sensor unit AS is visible in time to the control unit SE as an input signal, and vice versa. Therefore, based on an additional evaluation of the time distribution of the input signal and the corresponding facility state, the second wiring error VF2 can still be identified in inspection step 104. Therefore, it is advantageous to select sensor units DS, AS that send a quiescent signal (e.g., a current loop of 4 to 20 mA, a high-level active signal in a quiescent state, etc.) to the corresponding input terminals I1, I2 of the control unit SE when the supply voltage is already present in each associated load circuit. In this way, it is very easy to determine, for example, whether the correct sensor unit, actuator unit, etc. is being powered, or it is also possible to determine a possible cable break in the load circuit.

[0081] It should also be noted that the method according to the invention can be used not only in the case of a clock-controlled power supply SV, which converts the AC voltage applied to the input terminal into a constant DC output voltage, but also, for example, in the case of a regulated voltage source for AC current load units, thereby enabling the use of a wide range of electrical appliances to check the correct wiring or operation of these load units.

Claims

1. A method for inspecting the load circuits of a control system for a facility, wherein the control system includes, in addition to at least two load circuits, at least one control unit (SE) and a clock-controlled power supply (SV), wherein the at least two load circuits, each having at least one load unit, are supplied with a supply voltage and / or supply current by the clock-controlled power supply via at least two output channels (A1-A8), and wherein control signals are provided by the control unit (SE) to operate the at least two output channels (A1-A8), characterized in that... Perform the following steps: - Determine a reference current value at a predetermined voltage value of the supply voltage or a reference voltage value at a predetermined current value of the supply current for each predetermined facility state, wherein in the predetermined facility state, at least one output channel (A1-A8) is turned on and each associated load circuit is provided with the predetermined voltage value by the supply voltage or the predetermined current value by the supply current; - Store the reference current value or the reference voltage value determined for the given facility state; - During the self-test phase, for each pre-given facility state, measure the current value at each pre-given voltage value of the supply voltage or the current voltage value at each pre-given current value of the supply current on at least one on output channel (A1-A8). - Check whether, in one of the pre-given facility states, the currently measured current value of each when the supply voltage is at least one pre-given voltage value is compared with the corresponding stored reference current value, deviates from a pre-given tolerance range; or, in one of the pre-given facility states, the currently measured voltage value of each when the supply current is at least one pre-given current value is compared with the corresponding stored reference voltage value, deviates from a pre-given tolerance range. - And if it is determined that the load circuit deviates from the predetermined tolerance range at at least one predetermined voltage value of the supply voltage or at at least one predetermined current value of the supply current in one of the predetermined facility states, the corresponding load circuit is displayed.

2. The method according to claim 1, characterized in that, For each pre-given facility state, a reference voltage value for any output channel (A1-A8) to be shut down at least in each pre-given facility state is also determined and stored. During the self-test phase, the current voltage value is measured for the output channel (A1-A8) shut down in each current facility state, the measured voltage value is compared with the reference voltage value for the corresponding facility state, and the corresponding load circuit is displayed in the load circuit where the measured voltage value deviates from a pre-given tolerance range when compared with the respective stored reference voltage value.

3. The method according to any one of claims 1 to 2, characterized in that, For each pre-given facility state, a reference current value for shutting down any output channel (A1-A8) at least in each pre-given facility state is also determined and stored. During the self-test phase, the current value of the output channel (A1-A8) shut down in the corresponding facility state is measured, the measured current value is compared with the corresponding reference current value for the corresponding facility state, and the corresponding load circuit is displayed in the load circuit where the measured current value deviates from a pre-given tolerance range when compared with the respective stored reference current value.

4. The method according to any one of claims 1 to 2, characterized in that, The reference current value and the reference voltage value are determined with the aid of a reference facility for the corresponding facility status.

5. The method according to any one of claims 1 to 2, characterized in that, The reference current and reference voltage values ​​for the corresponding facility status are determined during the commissioning phase of the facility to be inspected or derived from the current and voltage values ​​measured on the corresponding output channels during continuous operation.

6. The method according to any one of claims 1 to 2, characterized in that, For each pre-given facility status, the reference values ​​of parameters and / or signals are detected and stored at the inputs (I1, I2) of the control unit (SE). During the self-test phase, the current values ​​of the parameters and / or signals at the inputs (I1, I2) of the control unit (SE) are queried for each pre-given facility status and compared with the corresponding reference values. The corresponding load circuit is also displayed, in which the current values ​​of the parameters and / or signals deviate from a pre-given tolerance range when comparing them with their respective stored reference values.

7. The method according to any one of claims 1 to 2, characterized in that, The pre-defined tolerance range is adapted for comparison of the current current value with the corresponding reference current value and / or comparison of the current voltage value with the corresponding reference voltage value.

8. The method according to any one of claims 1 to 2, characterized in that, The corresponding facility status, as well as the voltage values ​​of the power supply voltages or the current values ​​of the power supply currents of the corresponding output channels (A1-A8) that are respectively turned on and off, are preset by the control unit (SE).

9. The method according to any one of claims 1 to 2, characterized in that, A predefined waiting time is set between changing a predetermined voltage value of the supply voltage or a predetermined current value of the supply current in each predetermined facility state and determining the current value of the current measurement for the predetermined voltage value of the supply voltage.

10. The method according to any one of claims 1 to 2, characterized in that, The supply voltage is increased from the initial supply voltage to a predetermined nominal voltage or to the operating limit of at least one load unit connected to the corresponding load circuit by a predetermined voltage step.

11. The method according to any one of claims 1 to 2, characterized in that, The predetermined voltage value of the supply voltage is increased from the initial supply voltage to the predetermined nominal voltage or to the operating limit of at least one load unit connected to the corresponding load circuit in the form of a linear voltage ramp with a predetermined slope.

12. The method according to any one of claims 1 to 2, characterized in that, The determined reference current value and the determined reference voltage value are stored in the control unit (SE).

13. The method according to any one of claims 1 to 2, characterized in that, The determined reference current value and the determined reference voltage value are transmitted to the evaluation and / or data processing unit and stored there.

14. The method according to claim 13, characterized in that, The pre-given facility status is selected through the assessment and / or data processing unit.

15. The method according to claim 13, characterized in that, The currently measured current and / or voltage values ​​are forwarded to the evaluation and / or data processing unit and stored there.

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