Output device and method for operating an output device

Abstract

The present invention relates to an output device (2) having at least two power outputs (21, 22, 23, 24) for outputting electrical power, wherein: each of the at least two power outputs (21, 22, 23, 24) is assigned at least one individual switching element (11, 12, 13, 14); the outputting of the electrical power for each of the power outputs (21, 22, 23, 24) can be switched by means of the assigned individual switching element (11, 12, 13, 14); at least one superordinate switching element (10) is connected upstream of the individual switching elements (11, 12, 13, 14); the outputting of the electrical power for each of the power outputs (21, 22, 23, 24) can be switched by means of the superordinate switching element (10). The invention also relates to a method for operating an output device (2) having at least one switching element (10, 11, 12, 13, 14) designed to switch an associated power output (21, 22, 23, 24).

Description

[0001] EXIT DEVICE AND METHOD FOR OPERATING AN EXIT DEVICE

[0002] The present invention relates to an output device with at least two power outputs for outputting electrical power and to a method for operating an output device with at least one switching element configured for switching an associated power output.

[0003] In industrial automation, "output devices" are used to switch or control electrical power, for example, to execute specific actions in an automated system. Relays or semiconductor switches, as well as other types of switching elements, can be used.

[0004] Such an output device has, in particular, a power supply and at least one output, but especially an array of multiple outputs, for connecting devices and supplying them with electrical power. For example, field devices can be connected to an output device and supplied with electrical power via it; field devices include, for example, sensors and actuators, especially for industrial automation.

[0005] The output of electrical power to the connected devices can be controlled and adjusted via the output device, for example to limit or set voltage, current or power to a specific value, to switch the supply on or off, or to implement safety functions.

[0006] Such output devices can, for example, be controlled by a control system which sends signals to the output devices to, for example, switch on motors, open or close valves, activate heaters or perform other actions that are necessary for the operation of a system.

[0007] In automation technology, it is crucial that output devices respond reliably and accurately to the control signals from the control system to ensure the safe and efficient operation of the automated system. In particular, safe shutdown must be guaranteed in many applications.

[0008] The requirements for a high safety level are defined, for example, by the IEC 61508 standards, which provide a Safety Integrity Level (SIL) of SIL3. Another example is the EN ISO 13849 standard, which defines a Performance Level of level e, designated as "PLe".

[0009] For applications where the de-energized state is the "safe state," redundant shutdown paths must be provided for safe voltage disconnection so that a single fault does not lead to a loss of the safety function. A single fault occurs, for example, when semiconductor switches fail and can no longer be switched with high resistance. In the case of a relay switch, for instance, the contacts may weld together and no longer be able to open.

[0010] In addition to the redundant shutdown path, a simple fault must also be diagnosed.

[0011] In known solutions, for example, several semiconductor switches are connected in series for each safe output. If one switch loses its switching capability, this function can be taken over by another switch. However, the number of semiconductor switches correlates with higher costs, greater installation space requirements, and increased manufacturing effort; furthermore, power losses occur.

[0012] Furthermore, applications are known in which the power supply can be switched off by a higher-level semiconductor switch. If the higher-level semiconductor switch is tested by means of a switch-off pulse, then the downstream array of outputs is also briefly without power during these test shutdowns. This can be disadvantageous for certain applications, especially with cyclic test pulses on all outputs of the output array. EP 2 700 965 A2 discloses a semiconductor device for measuring the voltage of a battery cell. DE 10 2021 113 589 A1 proposes an electrical current distributor. DE 10 2010 008 973 A1 describes a tap changer with semiconductor switching elements.

[0013] It is an object of the present invention to ensure a high level of safety for an array of outputs in an output device, while keeping the number of disconnect elements to a minimum. Furthermore, good diagnostics are to be achieved, with the diagnostic process being possible with as little disruption as possible to connected devices.

[0014] This problem is solved according to the invention by an output device having the features of the device claim and a method for operating an output device having the features of the independent method claim. Advantageous embodiments are specified in the dependent claims.

[0015] The task is then solved by an output device with at least two power outputs for outputting electrical power; for example, a so-called "field" can have a large number of outputs, such as four, eight, or sixteen power outputs.

[0016] Each of the at least two power outputs is assigned at least one individual switching element, and the electrical power output can be switched for each output by means of the respective individual switching element. In particular, the power supply to a device connected to the assigned power output can be switched on or off by actuating the respective individual switching element.

[0017] Furthermore, at least one superior switching element is connected upstream of the individual switching elements, and the output of electrical power can be switched for each of the power outputs by means of the superior switching element.

[0018] In particular, this can mean that multiple power outputs, especially all power outputs of the output device, are grouped and assigned to the higher-level switching element. The power outputs grouped in this way can then be switched on or off simultaneously using the higher-level switching element. If necessary, the entire array of power outputs of an output device can be switched. Furthermore, an individual power output can be switched on or off using its respective assigned switching element.

[0019] This provides redundancy for shutdown capability: If, for example, an individual switching element cannot be reliably switched off, the higher-level switching element can take over this shutdown. Conversely, if the higher-level switching element cannot be reliably switched off, the individual switching elements can switch the individual power outputs on or off, for example, to establish a safe state for a connected device by switching off the electrical power supply.

[0020] The invention thus makes it possible to provide a functionally safe output device that has several safe outputs which can be switched individually.

[0021] The redundant shutdown elements used in known systems cause greater complexity, higher costs, more space requirements, and a certain amount of power loss. In contrast, the invention advantageously allows the safety requirements to be met with as few shutdown elements as necessary.

[0022] The number of switching elements required for the corresponding redundancy is reduced compared to known solutions where, for example, the individual switching elements are duplicated to provide two switching elements connected in series per power output.

[0023] In order to be able to safely switch off the outputs, in the event of a fault, such as a defective switching capability of an individual or the superior switching element, a further shutdown path is possible.

[0024] Furthermore, each switching element can be configured with high diagnostic coverage to ensure early fault detection. In this configuration, each individual switching element provides its own primary shutdown path for its assigned power outputs. The higher-level switching element also provides a common secondary shutdown path for all assigned power outputs. Specifically, a safe state for a power output can be activated by switching off via the individual primary shutdown path and / or the common secondary shutdown path. In particular, a "safe state" for a power output or a connected device can be defined as a de-energized state; in this case, switching off the electrical power supply via the power output results in the safe state.

[0025] The higher-level switching element can be, for example, a relay switch or a semiconductor switch.

[0026] Furthermore, at least one of the individual switching elements can be designed as a relay switch or semiconductor switch.

[0027] For example, relay switches can be particularly suitable for high-current applications due to their lower contact resistance. However, relay switches are more complex to implement in terms of electromechanical design, installation space, and component costs. Therefore, in many cases, only the main switch is designed as a relay switch, as it carries the total current and only needs to be implemented once for a given circuit.

[0028] In a further development process, the output device also includes a control unit. This unit can be configured, for example, to control the individual switching elements and / or the higher-level switching element. The control unit is configured to execute a diagnostic routine for the switching capability of the individual switching elements and / or the higher-level switching element. The diagnostic routine can be executed, for example, at periodic intervals, such as at specific time intervals, after a certain number of switching cycles, under specific operating conditions, or triggered by a control signal that the control unit can receive. In particular, the ability to shut down a power output or a connected device to achieve a safe state can be diagnosed.

[0029] For example, separate diagnostic routines can be provided for the individual switching elements and / or the higher-level switching element. Alternatively or additionally, a common diagnostic routine can be provided, for example, for several individual switching elements, for all individual switching elements, or for the individual switching elements and the higher-level switching element together.

[0030] The invention offers advantages with regard to the diagnosability of device malfunctions, particularly malfunctions concerning the ability to switch off the individual switching elements or the common switching element.

[0031] In known systems where a single shutdown element supplies several branches, i.e., in particular a field with many downstream power outputs, a shutdown of the upstream shutdown element in order to diagnose its shutdown capability leads to the simultaneous shutdown of all power outputs.

[0032] For example, if cyclical short shutdown pulses are executed at an upstream transistor switch to test its switching capability, these shutdown pulses also simultaneously affect the downstream outputs. In this case, the shutdown pulses occur at precisely the same time at multiple outputs, which can be disadvantageous depending on the application.

[0033] In the case of a relay switch upstream, frequent switching leads to mechanical wear, which limits its lifespan. Furthermore, the inertia of the ground must be overcome during the switching pulses of a relay switch. Therefore, test shutdowns to diagnose the switching capability are not possible as frequently and take longer.

[0034] During training, the diagnostic routine for a higher-level switching element designed as a semiconductor switch includes determining the junction capacitance, contact resistance, and / or control resistance of the higher-level switching element. For example, alloying can be detected based on the junction capacitance of a semiconductor switch. Furthermore, it may be necessary to determine the ratio between the contact resistance and the control resistance of the semiconductor switch; this value can also be used to determine the switching capability, in particular the turn-off capability, of the switching element.

[0035] In a further training, the diagnostic routine for a higher-level switching element designed as a relay switch includes executing a switch-off pulse immediately before a switch-on request for electrical power output. Specifically, the diagnostic routine, or the associated switch-off pulse, is already completed when the actual switching of the switching element occurs. It is therefore a test performed before the actual request.

[0036] Furthermore, a mixed configuration of semiconductor and relay switches may be present.

[0037] The diagnostic routine can be executed, in particular, for the higher-level switching element. The invention can then help to prevent switch-off pulses from simultaneously affecting all associated power outputs and from simultaneously disconnecting connected devices from power for a short period of time.

[0038] In a further training, a control unit is provided which is set up to receive an external control signal, in particular via a data interface of the output device, and to switch the individual switching elements and / or the superior switching element depending on the received control signal.

[0039] The control signal can, for example, be generated by an FS master device and transmitted to the output device. The external control signal can be configured, for example, to switch off the electrical power output through a specific power output, for instance, to establish a safe state. For this purpose, the individual switching element associated with the power output can be switched, or the higher-level switching element can be switched to switch an entire array of associated power outputs simultaneously. In the method for operating an output device with at least one switching element, in particular a higher-level switching element configured to switch an associated power output, a diagnostic routine is executed to diagnose the switching capability, in particular the ability to switch off, of the switching element; this can be done, in particular, at periodic intervals.For a switching element designed as a semiconductor switch, a junction capacitance, a contact resistance, and / or a control resistance of the switching element are determined, and / or for a switching element designed as a relay switch, a switch-off pulse is executed immediately before a switch-on request for the output of electrical power. During the diagnostic routine, a diagnostic parameter is acquired, and a state value of the switching element is determined based on this parameter. The state value can, for example, qualitatively indicate whether or not a fault condition of the switching element exists; alternatively or additionally, it can quantitatively indicate a measure of the switching capability of the switching element, for example, to detect deterioration. Depending on the state value thus determined, a control signal is generated to activate a safe state for the associated power output.

[0040] The method is specifically designed to operate an output device as described herein. It therefore offers the same advantages as the output device and can be further developed analogously. Conversely, the output device of the method also offers the same advantages and can be further developed analogously.

[0041] During training, to activate a safe state for the assigned power output or a connected device, a shutdown is performed via an alternative shutdown path. Specifically, the shutdown is carried out via an alternative shutdown path, meaning that the shutdown is performed using the other individual or higher-level switching element assigned to a power output.

[0042] Further details and advantages of the invention will now be explained in more detail with reference to an exemplary embodiment shown in the drawings.

[0043] Figure 1 shows a first embodiment of the output device; and

[0044] Fig. 2 shows a second embodiment of the output device.

[0045] With reference to Fig. 1, a first embodiment of the output device is explained.

[0046] A system 1 with an output device 2, an FS master 3 and a power supply 9 is shown.

[0047] Output device 2 is specifically designed to supply electrical energy to field devices such as sensors or actuators in industrial automation.

[0048] For this purpose, output device 2 has a power input 18. This is connected to an external power supply 9 via a line 8. The external power supply 9 supplies the output device 2 with electrical power via line 8 and power input 18.

[0049] In this example, output device 2 has four power outputs 21, 22, 23, 24. These are configured as output terminals 21, 22, 23, 24 in a manner known per se and are suitable for supplying electrical power to connected devices.

[0050] In typical further embodiments, 4, 8 or 16 outputs may be provided.

[0051] The output device 2 also has a 0 V terminal 28.

[0052] Each of the four power outputs 21, 22, 23, 24 is assigned an individual switching element 11, 12, 13, 14.

[0053] In this example, the individual switching elements 11, 12, 13, 14 are configured as semiconductor switches 11, 12, 13, 14 in a manner known per se. The individual switching elements 11, 12, 13, 14 are configured to control the output of electrical power to their respective associated power outputs 21, 22, 23, 24. Specifically, the individual switching elements have an open and a closed state, whereby in the open state the associated power output 21, 22, 23, 24, or a device connected to it, is de-energized.

[0054] In this embodiment, the power outputs 21, 22, 23, and 24 are designed to achieve a high level of safety. This is based on the relevant standards, such as IEC 61508, SIL3, or EN 13849, PLe. It must be ensured that a fault does not lead to the loss of the safety function. The "safe state" is defined here as the absence of any voltage output. To provide the necessary redundancy, two switches in series are required, as a single switch could malfunction, preventing the voltage from being switched off or maintained.

[0055] The output device 2 has a master switching element 10, which in this example is designed as a semiconductor switch in a manner known per se and which is connected upstream of the individual switching elements 11, 12, 13, 14. In this example, the master switching element 10 is connected in series with the individual switching elements 11, 12, 13, 14, while the individual switching elements 11, 12, 13, 14 are connected in parallel with each other. This means that by switching the master switching element 10, the associated individual switching elements 11, 12, 13, 14 can be switched together.

[0056] In particular, switching the higher-level switching element 10 can establish or break an electrical connection between the power outputs 21, 22, 23, 24 and a positive potential 26 (24 V in this example). Switching the higher-level switching element 10 affects all four associated power outputs 21, 22, 23, 24 equally; specifically, when the connection is opened, all four are simultaneously de-energized.

[0057] The output device 2 therefore has a master switch 10, through which the array of outputs 21, 22, 23, 24, connected via a line 7, is supplied with electrical power and which serves as a second shutdown path in addition to a first, individual shutdown path via the individual switching elements 11, 12, 13, 14 for the respective assigned power output 21, 22, 23, 24. The individual switching elements 11, 12, 13, 14 each provide an individual first shutdown path for the assigned power output 21, 22, 23, 24. The master switching element 10 also provides a common second shutdown path for the assigned power outputs 21, 22, 23, 24. The first shutdown path allows the power outputs 21, 22, 23, 24 to be switched independently of each other by switching the individual switching elements 11, 12, 13, 14.In contrast, the second shutdown path switches the entire array of power outputs 21, 22, 23, 24 together and simultaneously by switching the superior switching element 10.

[0058] The output device further comprises at least one data interface 17, in particular a communication port 17. The data interface 17 is connected to an FS master 3 via a data line 6. Control signals can be received from the FS master 3 via the data interface, data can be output, and / or data can be exchanged bidirectionally.

[0059] For example, the data can include information on switching on and off or on a switching state of the power outputs 21, 22, 23, 24.

[0060] For example, a physical bus such as IO-Link or Single Pair Ethernet (SPE) can be provided.

[0061] In this example, output device 2 communicates using a safety protocol, such as IO-Link Safety Protocol, Profisafe, CIP Safety, CANopen Safety, or a proprietary safety protocol.

[0062] The output device 2 also includes a control unit 4, which in this example is configured as a safety logic 4. It incorporates a redundant structure and includes, for example, a redundant arithmetic logic unit (ALU), a redundant microprocessor (MCU), and redundant random access memory (RAM) or read-only memory (ROM). In particular, safety-relevant data is processed redundantly and cross-checked. Similarly, in this example, the FS master 3 also includes a control unit 5, which for the purposes of this description is likewise configured as a safety logic 5.

[0063] The control unit 4 of the output device 2 is configured to control the individual switching elements 11, 12, 13, 14 so that they can be opened and closed. It is also configured to control the higher-level control element so that it can be opened and closed.

[0064] The control unit 4 is further equipped to perform a diagnostic routine at periodic intervals for the switching capability of the individual switching elements 11 , 12, 13, 14 and the superior switching element 10.

[0065] In this embodiment, the individual switching elements 11, 12, 13, 14 and the higher-level switching element 10 are designed as semiconductor switches. The diagnostic routine includes determining the junction capacitance of each semiconductor component. The junction capacitance can be used to detect, for example, when a semiconductor switch is shorted and no longer able to switch off.

[0066] Alternatively or additionally, a contact resistance and a control resistance can be determined in order to diagnose the switching capability.

[0067] In the first described embodiment, the output device 2 has a master semiconductor switch 10 that supplies an array of outputs 11, 12, 13, 14. If this master semiconductor switch 10 were tested using a shutdown pulse, all outputs would synchronously emit this shutdown pulse. This could lead to problems, as the output signals could then not be distinguished based on their pulsing. A cross-circuit fault could also lead to synchronous pulses. Therefore, some actuators, such as inverters, require that the pulses not occur synchronously. The invention now makes it possible to test the master semiconductor switch 10 in a different way. In one embodiment, the semiconductor switch achieves its diagnostic coverage by not being fully switched on, but rather controlled via a feedback loop. The controlled variable is the voltage drop across the semiconductor path.If the semiconductor switch is alloyed, the controlled variable will not remain constant, so that the switching capability can be monitored in the switched-on state and the desired high diagnostic coverage is maintained.

[0068] In another embodiment, diagnostic coverage for the semiconductor switch is achieved by measuring its junction capacitance. For this purpose, a second capacitor is connected in series with the junction capacitance, and the voltages across the two capacitors are measured as they are distributed relative to their capacitance values. The measurement can be performed cyclically and can be designed so that the junction capacitance remains sufficiently charged during the measurement, thus preventing the semiconductor switch from being turned off. Since the junction capacitance changes when the semiconductor element is alloyed, this fault can be diagnosed in this way.

[0069] This allows the shutdown capability to be tested in the switched-on state in such a way that a sufficiently high diagnostic coverage is achieved.

[0070] With reference to Fig. 1, an exemplary embodiment of a method for operating the output device 2 described above is further explained. This assumes the output device 2 described above.

[0071] A diagnostic routine is executed periodically to assess the switching capability of one of the individual switching elements 11, 12, 13, 14 or of the higher-level switching element 10. This involves diagnosing the switching capability of switching element 10, 11, 12, 13, 14. Specifically, the diagnostic routine is performed periodically for all switching elements 10, 11, 12, 13, 14.

[0072] For a switching element 10, 11, 12, 13, 14 designed as a semiconductor switch, a junction capacitance is determined in the exemplary embodiment. Alternatively or additionally, a contact resistance and a control resistance of the switching element 10, 11, 12, 13, 14 can be determined. By determining the junction capacitance, the switching capability of a semiconductor switch 10, 11, 12, 13, 14 can be tested without having to switch it off for testing purposes. Thus, no switch-off pulse needs to be used to test the switch. This means that for the higher-level switching element 10, it is avoided that switch-off pulses affect the entire field of the associated power outputs 21, 22, 23, 24 as well as the connected devices.

[0073] In this embodiment, it is therefore particularly intended that the superior switching element 10 achieves a high diagnostic coverage without having to be cyclically switched off.

[0074] For a switching element 10, 11, 12, 13, 14 designed as a relay switch (an exemplary case of such an output device 30 is explained below), a switch-off pulse is executed immediately before a switch-on request for the output of electrical power by the switching element 10, 11, 12, 13, 14.

[0075] In general, during the diagnostic routine, a diagnostic parameter is recorded and, depending on the diagnostic parameter, a state value of the switching element 10, 11, 12, 13, 14 is determined.

[0076] The diagnostic parameter can in particular be an electrotechnical parameter of the switching element 10, 11, 12, 13, 14, such as an electrical characteristic or a parameter that describes the switching behavior of the switching element 10, 11, 12, 13, 14.

[0077] The status value can, for example, qualitatively indicate whether or not a fault condition exists in the switching element 10, 11, 12, 13, 14. Alternatively or additionally, it can quantitatively indicate a measure of the switching capability of the switching element, so that, for example, deterioration can be detected.

[0078] Depending on the state value, a control signal is generated to activate a safe state for the assigned power output 21 , 22, 2,3 24.

[0079] A safe state can be defined, for example, as a de-energized state. Therefore, if it is determined that a safe shutdown is no longer possible via one of the shutdown paths, then the associated power output 21, 22, 23, 24 or the entire array of outputs can be de-energized by using the other shutdown path.

[0080] With reference to Fig. 2, a second embodiment of the output device is explained. This embodiment is based on the first embodiment described above, and only the differences are explained in more detail.

[0081] In the second embodiment, the higher-level switching element 25 is designed as a relay switch 25. This opens or closes an electrical connection between the downstream power outputs 21, 22 and a positive potential 26 with a voltage of 24 V.

[0082] Furthermore, similar to the first embodiment described above, individual semiconductor switches 11, 12 are provided and assigned to the power outputs 21, 22.

[0083] In the second embodiment, it is further provided that the output device 2 is supplied with multiple voltages. In particular, the voltages for the safety logic 4 and for data communication can be routed separately from the power supply for the power outputs 21, 22.

[0084] If communication and logic have a different potential than the power outputs, then the control signals and feedback signals can be routed via galvanic isolators, such as optocouplers 15, 16, inductive couplers, capacitive couplers, or similar devices. In particular, it is advantageous to read the inputs without potential contact, for example, via optocouplers 15, 16. Such an output device 2 can also operate as an input device without connecting the output voltage, provided that the logic voltage 42 is supplied at a terminal 41.

[0085] Another method for operating the output device 2 with a higher-level semiconductor switch 10 comprises the following steps:

[0086] 1. In standby mode, the outputs detect that no voltage is applied;

[0087] 2. Activation command of an output via secure communication;

[0088] 3. Switching on the higher-level semiconductor switch;

[0089] 4. Detect that no voltage is present at any output; 5. Start and perform the test of the higher-level semiconductor switch (cyclically or continuously);

[0090] 6. Switching on the subordinate semiconductor switch

[0091] 7. Determine that a voltage is present at the switched-on output; and

[0092] 8. Start and perform the testing of the subordinate semiconductor switch (cyclically or continuously).

[0093] Another method for operating the output device 2 with a higher-level relay switch 25 comprises the following steps:

[0094] 1. In standby mode, the outputs detect that no voltage is applied;

[0095] 2. Activation command of an output via secure communication;

[0096] 3. Detect that the relay contact is in the off state;

[0097] 4. Activation of the higher-level relay switch;

[0098] 5. Detect that the relay contact is no longer in the off state;

[0099] 6. Determine that there is no voltage at any output;

[0100] 7. Switching on the subordinate semiconductor switch;

[0101] 8. Determine that a voltage is present precisely at the switched-on output; and

[0102] 9. Starting and performing the test of the subordinate semiconductor switch (cyclically or continuously)

[0103] Another procedure for shutdown in case of a fault includes the following steps:

[0104] 1. It is recorded that a test for a switching element 10, 11, 12, 13, 14 fails or the actual state of a feedback does not correspond to the target state;

[0105] 2. Switch off all switches, especially both serial switches;

[0106] 3. Non-emotional vomiting and reporting of the error; as well as

[0107] 4. Do not allow it to be switched on again.

[0108] A small current flow may be necessary for testing a semiconductor. For this purpose, an internal load resistor can be provided, resulting in a defined current flow at an applied voltage. It can be advantageous that a fault in one switching element does not cause other switching elements to be energized. Therefore, in an array of semiconductor switches connected at one end, a diode can be provided in each path to prevent backfeeding when an external power supply is applied.

[0109] To obtain a safe output device, a sufficiently high diagnostic coverage for the switches is required; that is, a simple fault must be detected with a high probability.

[0110] In the case of semiconductor switches 10, 11, 12, 13, 14, such diagnostic coverage can be achieved by testing, whereby an output switch is cyclically briefly switched off and the remaining voltage is determined. Depending on the frequency of the requirement, the test cycle can be set to achieve high diagnostic coverage. A typical example is a cycle of approximately one second and a switch-off pulse of one millisecond.

[0111] A changeover contact 25 can be used to diagnose relay switches, where the normally closed contact is detected. The error of both the normally closed and normally open contacts being closed simultaneously can be ruled out. This allows testing before the safety function is required.

[0112] Diagnostic coverage is classified into the following levels according to ISO 13849-1:

[0113] • 60% to 90% -> low

[0114] • 90% to 99% -> medium

[0115] • Over 99% -> high

[0116] One objective is to achieve high diagnostic coverage, or at least medium diagnostic coverage, with regard to the switching capability of the upper switch. This can be achieved by the present invention. Reference numeral list

[0117] 1 system

[0118] 2 Output Device

[0119] 3 FS-Master

[0120] 4 Control unit, safety logic (of the output device)

[0121] 5 Control unit, safety logic (of the power supply)

[0122] 6 lines (data)

[0123] 7 Management

[0124] 8 Line (electrical power)

[0125] 9 Benefit provision

[0126] 10. Higher-level switching element, semiconductor switch

[0127] 11, 12, 13, 14 Individual switching element, semiconductor switch

[0128] 15, 16 Optocouplers

[0129] 17 Data interface, communication port

[0130] 18 Power input

[0131] 20 Ground potential terminal (0 V)

[0132] 21, 22, 23, 24 Power output, output terminal

[0133] 25. Superior switching element, relay switch

[0134] 26 Plus potential (24 V)

[0135] 27 Ground potential (0 V)

[0136] 28 Ground potential terminal (0 V)

[0137] 40 System

[0138] 41 Plus potential terminal (24 V)

[0139] 42 Plus potential (24 V)

Claims

Patent claims 1. Output device (2) with at least two power outputs (21, 22, 23, 24) for outputting electrical power; wherein each of the at least two power outputs (21, 22, 23, 24) is assigned at least one individual switching element (11, 12, 13, 14); wherein the output of electrical power for each of the power outputs (21, 22, 23, 24) can be switched by means of the respective assigned individual switching element (11, 12, 13, 14); wherein at least one superior switching element (10) is connected upstream of the individual switching elements (11, 12, 13, 14); wherein the output of electrical power for each of the power outputs (21, 22, 23, 24) can be switched by means of the superior switching element (10).

2. Output device (2) according to claim 1, characterized in that the individual switching elements (11, 12, 13, 14) each provide an individual first shutdown path for the associated power outputs (21, 22, 23, 24) and the superior switching element (10) provides a common second shutdown path for the associated power outputs (21, 22, 23, 24); wherein, in particular, a safe state for a power output (21, 22, 23, 24) can be activated by switching off using the individual first shutdown path and / or the common second shutdown path.

3. Output device (2) according to one of the preceding claims, characterized in that several power outputs (21 , 22, 23, 24), in particular all power outputs (21 , 22, 23, 24) of the output device (2), are grouped and assigned to the superior switching element (10) so that they can be switched on or off simultaneously by means of the superior switching element (10).

4. Output device (2) according to one of the preceding claims, characterized in that the superior switching element (10, 25) is a relay switch (25) or a semiconductor switch (10).

5. Output device (2) according to one of the preceding claims, characterized by a control unit (4) which is configured to perform, in particular at periodic intervals, a diagnostic routine for the switching capability of the individual switching elements (11 , 12, 13, 14) and / or the superior switching element (10).

6. Output device (2) according to claim 5, characterized in that the diagnostic routine for a higher-level switching element (10) designed as a semiconductor switch (10) comprises determining a junction capacitance, a contact resistance and / or a control resistance of the higher-level switching element (10).

7. Output device (2) according to claim 5 or 6, characterized in that the diagnostic routine for a superior switching element (25) designed as a relay switch (25) comprises executing a switch-off pulse immediately before a switch-on request for output of electrical power.

8. Output device (2) according to one of the preceding claims, characterized in that the control unit (4) is configured to receive an external control signal, in particular via a data interface (17) of the output device (2), and to switch the individual switching elements (11 , 12, 13, 14) and / or the superior switching element (10) depending on the received control signal.

9. Method for operating an output device (2) with at least one switching element (10, 11, 12, 13, 14) configured to switch an associated power output (21, 22, 23, 24); wherein - a diagnostic routine is executed to diagnose the switching capability of the switching element (10, 11, 12, 13, 14), in particular at periodic intervals; wherein - for a switching element (10, 11, 12, 13, 14) designed as a semiconductor switch, a junction capacitance, a contact resistance and / or a control resistance of the switching element (10, 11, 12, 13, 14) is determined; and / or for a switching element designed as a relay switch Switching element (25) a switch-off pulse is executed immediately before a switch-on request for the output of electrical power; wherein - during the diagnostic routine, a diagnostic parameter is recorded and, depending on the diagnostic parameter, a status value of the switching element (10, 11, 12, 13, 14) is determined; and - depending on the state value, a control signal is generated to activate a safe state for the associated power output (21 , 22, 23, 24).

10. Method according to the preceding method claim, characterized in that a shutdown is carried out via an alternative shutdown path to activate a safe state for the associated power output (21 , 22, 23, 24).

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