VALVE CONTROL UNIT

Description

[0001] The invention relates to a valve control device according to the preamble of the first claim and a method according to the preamble of the eighth claim.

[0002] Valves are used in plants for the production of food, beverages, pharmaceuticals, and fine chemical products, as well as in biotechnology. Due to the size of such plants and the degree of automation, the valves are often equipped with valve control devices attached to them.

[0003] A combination of a valve and a valve control unit is presented in WO 2006 / 084541 A1. The valve control unit ensures switching of the valve state, for example, between the states "open," in which fluid flow through the valve is permitted, and "closed," in which fluid flow is prevented.

[0004] The valve control unit controls the actuator, which is often, but not necessarily, pneumatic. This control system includes at least one so-called pilot valve, which can allow pneumatic air to flow into the actuator to activate it and thus change the switching state of the valve.

[0005] In addition to this switching function, the valve control unit is equipped with sensors that allow the switching state of the valve to be determined.

[0006] The valve control unit has a communication interface to receive control commands, for example, via a bus from a system controller, and to report the switching status to it. WO 2006 / 084541 A1 describes a convenient design for providing various bus standards.

[0007] The use of near-field communication interfaces in connection with field devices, such as valve control units, is more recent. Near-field communication is used to communicate with the field device directly, or via a relay in the case of a field device installed in a difficult-to-access location, in the vicinity of the device, without having to go through the system control system. This is necessary, for example, for maintenance and inspection work. Such an arrangement is known, for example, from WO 2020 / 114719 A1.

[0008] US 2017 / 0218601 A1 describes a controller for adjusting the outlet pressure of a pressure reducing valve for a water supply. Communication between components of the described controller can be via wired connections, a bus, FireWire, LAN or WAN, optical fiber connections, short-range wireless communication such as infrared, inductive coupling, Bluetooth, Wi-Fi, or long-range communication using suitable radio frequencies and protocols or mobile networks, for example, using SMS.

[0009] US 2016 / 0018829 A1 and CN 103075536 A describe valve control units in which near-field communication or communication via a BUS can take place.

[0010] EP 2 597 779 A1 describes a near-field communication device that can be used, for example, in electronic ticket systems. During maintenance work, it is important to ensure that a valve reaches and maintains a switching state necessary for the work while the work is in progress. Unintentional switching must be avoided.

[0011] The task was therefore to create a valve control unit that allows safe maintenance work on the valve.

[0012] This object is achieved by a valve control device according to claim 1 and a method according to claim 8. Advantageous further developments are specified in the dependent claims.

[0013] The starting point is a valve control unit with at least one switching stage, control electronics for controlling the switching stage and a BUS interface for communication with a higher-level system control of a process plant.

[0014] In this context, BUS includes the common bus systems used in automation technology in plant engineering, including parallel wiring, in which the individual devices are connected directly to the plant control system.

[0015] This valve control unit now features a near-field communication interface, and the control electronics are configured to give priority to a control command received via the near-field communication interface for controlling the switching stage. Priority means that the control electronics are in an operating state in which only a command received via the near-field communication interface is used to effectively control the switching stage. A command received simultaneously from the system control via the bus interface is not used in this operating state. This is regardless of whether feedback, for example regarding the switching state of the valve, is also sent to the system control at the same time. The command received from the system control can still be signaled to the operator as a notification via the access device.

[0016] For a method for operating an arrangement with a valve control unit, which comprises a first near-field communication interface and a bus interface, and an access device with a second near-field communication interface, it is proposed that, in one step, a near-field connection is established between the first and second near-field communication interfaces. In a further step, a control command is sent via the near-field connection. An additional step involves giving this control command priority over a command received by the valve control unit via the bus interface.

[0017] The drive can be electrically operated. In this case, the switching stage includes an electronic switching device, such as a thyristor, to switch the current supply to a power component, such as an electric motor.

[0018] The drive can be hydraulic or pneumatic. In this case, the switching stage comprises at least one pilot valve, which switches the supply of hydraulic or pneumatic fluid to the drive. In this embodiment, a valve control unit is provided with a pilot valve, control electronics for controlling the pilot valve, and a bus interface for communication with a system controller of a process plant. To achieve this objective, a near-field communication interface is provided in the valve control unit, and the control electronics are configured to give priority to a control command received via the near-field communication interface for controlling the pilot valve.

[0019] The valve control unit's configuration for this functionality can include a selector in the valve control unit, by means of which selector a control command received via the near-field communication interface can be selected for execution. The selector can be implemented as a circuit or as a software routine, which software routine can be executed by a microprocessor provided in the valve control unit. The selector can be implemented as part of the control electronics or as a standalone module.

[0020] This ensures that the operator on site has complete control over the valve's switching state. Switching by the system control system is suppressed at this time.

[0021] In an arrangement comprising a valve control unit and an access device, the near-field communication interface of the valve control unit is connected to a

[0022] The access device can be connected to the near-field communication interface of an access device. The access device can be mechanically and detachably connected to the valve control unit. A coupling can be provided for the mechanical connection, for example, based on a magnetic principle or designed as a suction cup.

[0023] The above-mentioned method is advantageously supplemented by a process step in which a mechanical connection is established between the valve control unit and the access device. This ensures that the correct devices are linked to each other and that the data connection is secured by mechanical coupling.

[0024] This advantage is enhanced if, according to a further development, near-field communication is established between the first and second near-field communication interfaces when the mechanical connection exists.

[0025] The access device preferably has a display panel and at least one button for operation. Data can be exchanged via the wireless data connection of the near-field communication interfaces, for example, control commands for changing the valve position, measurement and status data, such as valve position. A control command also includes a command that starts a sensor calibration, also known as "teach-in." The data can also be suitable for parameterizing or configuring the valve control unit. The data can, for example, be a firmware update. Status data recorded in the valve control unit over a period of time can also be retrieved via near-field communication.

[0026] Since the control electronics uses control commands received via the near-field communication interface to achieve a desired valve position, the access device acts as a control unit to adjust the valve position independently of the system control system. This is very useful during maintenance work because the service technician can adjust the valve state directly at the valve, eliminating the need for interaction with the system control system.

[0027] The access device can be configured to perform a password query, which protects it against unauthorized operation. This password query can be initiated by the system controller via the bus, the bus interfaces, and the interconnected near-field communication interfaces.

[0028] The access device can be configured to block the valve control unit from the system control system. This makes maintenance work safer, for example. To achieve this, the control electronics are configured to block control commands from the system control system that can be sent via the bus interface in accordance with a blocking command received via the near-field communication interface.

[0029] In addition to control elements and the near-field communication interface, the access device can have at least one far-field communication interface, for example, based on the Wi-Fi or WLAN standard. Communication with a server, triggered, for example, by the operator, can take place via the far-field communication interface via the internet. A connection can be established to a mobile control device. This mobile control device, for example, a tablet or a mobile phone, can send control commands to the valve device via the access device, which trigger the activation of at least one pilot valve and, via this, the actuator.

[0030] The valve control unit may have a display element, for example a light-emitting diode, which indicates data transmission via the near-field communication interface.

[0031] It is advantageous to equip the valve control unit with a manual control element, which allows an operator to manually operate the pilot valve(s) to control the actuator, independently of and with priority over the control commands originating from the system control or access device. The resulting priority of the control commands ensures maximum safety during maintenance work in the vicinity and on the valve. The manual control element has the highest priority, followed by the access device, which has a higher priority than the system control.

[0032] The invention will be explained and its advantages will be presented in more detail using an exemplary embodiment and its further development.

[0033] They show: Fig. 1: Schematic representation of an arrangement with a valve control unit; Fig. 2: Schematic representation of some components in the access device and valve control unit.

[0034] In Fig. 1 An arrangement comprising a valve 1, a valve control device 2, and an access device 3 is schematically shown. The valve 1 can be a shut-off valve installed in a line 4 of a process plant, particularly in the industrial fields mentioned above. It can also be a control valve, double-seat valve, changeover valve, or the like, provided that the valve type is used in this application.

[0035] A drive 5 is arranged between valve 1 and valve control unit 2. In this exemplary embodiment, this drive is designed to be pressure-operated, particularly pneumatically operated. The drive causes a change in the position of a closing body of valve 1 (not shown in the diagram), thereby changing the switching state of valve 1. In particular, valve 1 can block the fluid flow through line 4 in a closed position or release it in an open position.

[0036] The actuator 5 is activated by the valve control unit 2. In the case of a pneumatic actuator, this is done via compressed air, which is fed into the actuator 5 to move a piston that is operatively connected to the closing body in the valve 1. The compressed air is taken from a pressure medium supply line 6.

[0037] For control operation, the valve control unit 2 is connected to a system controller 7. This connection can be implemented via a bus 8 of the process plant, to which the valve control unit 2 is connected via a bus connection 9 for data exchange. Bus 8 and bus connection 9 are often wired. The data exchange includes, in particular, control commands, which are converted by the valve control unit 2 into a change in the switching state of the valve 1. Another part of the data can be, for example, the message of the current switching state.

[0038] The access device 3 is mechanically and detachably coupled to the valve control unit 2. A mechanical coupling 10 is provided for this purpose. The mechanical coupling can, for example, be based on a magnetic operating principle or be designed as a suction cup. The mechanical coupling 10 can comprise parts on the valve control unit 2 and the access device 3. Alternatively, for example, in the version with a suction cup, the mechanical coupling 10 can be arranged entirely on the valve control unit 2 or the access device 3.

[0039] The access device 3 has operating and display elements, for example, a display panel 11 and at least one button 12. The operating and display elements are adapted to the data and control commands to be processed and displayed in the access device 3, as well as to the application environment, for example, a hygienic and clean installation area. A touchscreen, for example, is also conceivable.

[0040] The access device can be designed such that it can be connected to a mobile operating device 14 for data transfer 13. This mobile operating device 14 can be a tablet, a smartphone, a laptop, or the like.

[0041] In Fig. 2 functional assemblies of the valve control unit 2 and the access device 3 are shown schematically.

[0042] The core of the valve control unit 2 is an electronic control unit 15. This unit interacts with a driver 16, by means of which the switching position of a pilot valve 17 can be changed between open and closed. In this exemplary embodiment, the pilot valve 17 functions as a switching stage. The switching position of the pilot valve 17 determines whether pressure medium flows from the pressure medium supply line 6 to the pressure medium outlet 18, which is fluidly connected to the drive 5. The driver 16 can be designed, for example, on an electromagnetic basis.

[0043] The pilot valve 17 is controlled according to control commands from the system control system 7. These control commands are transmitted to the valve control unit 2 via the bus 8. The bus connection 9 is operatively connected to a bus interface 19 in the valve control unit 2. The bus interface 19 transmits the control commands, if necessary in an adapted form, to the control electronics 15.

[0044] In addition to the bus interface 19, the valve control unit 2 has a first near-field communication interface 20.

[0045] A second near-field communication interface 21 is provided in the access device 3.

[0046] A near-field connection 22 for transmitting data, in particular control commands, can be established between the first and second near-field communication interfaces 20 and 21. The advantage of such a near-field connection 22 is that it provides secure communication between the valve control unit 2 and the access device 3. The two devices, brought into mechanical contact, for example, by the action of the mechanical coupling 10, communicate in a targeted manner. This prevents interference with third-party devices, such as the valve control units of neighboring valves. Near-field communication largely prevents interference with neighboring devices.

[0047] The valve control unit includes a selector 23 that is operatively connected to the bus interface 19 and the first near-field communication interface 21. This selector 23 can be a standalone module, for example, based on logic modules. Alternatively, it can be part of the control electronics 15. Regardless of its location, it can also be implemented as software.

[0048] The selector 23 is configured to transmit a control command for changing the switching position of valve 1, which causes the activation of the pilot valve 17, to the control electronics 15 for execution according to a defined priority order. If similar control commands are received simultaneously or at a similar time via the bus interface 19 and the first near-field interface 20, only the one received via the near-field interface 20 is forwarded to the control electronics 15 for processing. This makes the valve 1 reliably switchable for an operator in the immediate spatial vicinity of the valve 1.

[0049] It is advantageous to provide a manual control element 24 with which the pilot valve 17 can be manually switched by the operator. This manual control element 24 actuates the pilot valve 17 independently of control commands received from the control electronics 15. The manual control element 24 is therefore of the highest priority. Preferably, it is only accessible to the operator when a housing of the valve control unit 2 is open. If multiple pilot valves 17 are present, multiple manual control elements 24 can be provided, each of which is assigned to a pilot valve 17.

[0050] In addition to controlling the pilot valve 17, the access device 3 can be designed to perform further functions that can be implemented in interaction with the correspondingly designed valve control device 2.

[0051] For example, error and diagnostic data can be read from an error memory provided in the valve control unit and displayed. The stroke can be adjusted, and tolerances of the valve closing element's position values ​​can be read and adjusted. Access device 3 can act as a data logger.

[0052] The access device 3 can comprise a remote field communication interface 25, with which a remote field connection 26 can be established to another device, for example, the mobile operating device 14. The remote field connection can be based on a WLAN or Wi-Fi standard. Data can be exchanged with devices on the Internet via the remote field connection, for example, the transmission of error logs and parameters that allow and trigger the ordering of spare parts.

[0053] The valve control unit can have a display element 27 that sends signals visible to the operator, for example, optical signals. This display element 27 can be used, for example, to indicate active data transmission via the near-field connection. In a cost-effective embodiment, the display element 27 comprises an LED.

[0054] The basis of the Fig. 1 and Fig. 2 The arrangement explained with a valve control device 2 and an access device 3 is preferably operated with a method which essentially comprises the following steps: A near-field connection 22 is established between the first near-field communication interface 20 on the valve control unit 2 and the second near-field communication interface 21 on the access device 3. A control command is sent via the near-field connection 22. This control command is given priority over a command received from the valve control unit 2 via the bus interface 19.

[0055] This method allows an operator of the system, who, for example, wishes to perform maintenance work, to adjust the switching state of the valve to suit their needs using an access device 3. This advantageously prevents the switching state from being inadvertently changed by the operator via the bus interface 19 for the duration of the near-field connection 22. This increases operator safety.

[0056] In order to specifically bring a specific valve control unit 2 into the state desired by the operator and to keep it safely in this state, an additional step can be provided for establishing a mechanical connection between the valve control unit 2 and the access device 3.

[0057] The security is further increased if the method also comprises that a near field connection 22 is established between the first and second near field communication interfaces 20 and 21 when the mechanical connection exists. List of reference symbols

[0058] 1Valve 2Valve control unit 3Access device 4Line 5Drive 6Pressure medium supply line 7System control 8Bus 9Bus connection 10Mechanical coupling 11Display panel 12Button 13Data transfer 14Mobile control unit 15Control electronics 16Driver 17Pilot valve 18Pressure medium outlet 19Bus interface 20First near-field communication interface 21Second near-field communication interface 22Near-field connection 23Selector 24Manual control element 25Far-field communication interface 26Far-field connection 27Display element

Claims

1. A valve control device having a switching stage, control electronics (15) for controlling the switching stage and a bus interface (19) for communication with a plant controller (7) of a processing plant, characterized in that a near-field communication interface (20) is provided in the valve control device (2) and the control electronics (15) are designed to give priority to a control command arriving via the near-field communication interface (20) for controlling the switching stage.

2. The valve control device according to claim 1, characterized in that a selector (23) is provided, said selector transmitting control commands, which arrive via the near-field communication interface (20), to the control electronics (15) with priority over the bus interface (19).

3. The valve control device according to claim 1, characterized in that the control electronics (15) are designed to block control commands of the plant controller (7), which can be transmitted via the bus interface (19), according to a blocking command arriving via the near-field communication interface (20).

4. The valve control device according to one of the preceding claims, characterized in that the switching stage comprises a pilot valve (17).

5. The valve control device according to claim 4, characterized in that a manual control element (24) is provided, the pilot valve (17) being able to be controlled thereby so as to override the control electronics (15).

6. An arrangement having a valve control device (2) according to one of the preceding claims and an access device (3), characterized in that the access device (3) comprises a second near-field communication interface (21) and can be mechanically connected to the valve control device (2).

7. The arrangement according to claim 6, characterized in that the access device (3) has a far-field communication interface (25).

8. A method for operating an arrangement having a valve control device (2), which comprises a first near-field communication interface (20) and a bus interface (19), and an access device (3) having a second near-field communication interface (21), characterized in that a near-field connection (22) is established between the first and the second near-field communication interface (20, 21), a control command is transmitted via the near-field connection (22) and priority is given to this control command over a command which is received by the valve control device (2) via the bus interface (19).

9. The method according to claim 8, characterized in that a mechanical connection is established between the valve control device (2) and the access device (3).

10. The method according to claim 9, characterized in that a near-field connection (22) is established between the first and the second near-field communication interface (20, 21) when the mechanical connection is present.