RAIL-MOUNTED DEVICE, AUTOMATION SYSTEM AND METHOD FOR PROCESS AUTOMATION

Abstract

A rail-mounted device for automation systems having at least one local bus interface for connecting the rail-mounted device to a local bus of an automation system, and a power supply unit that has at least one input and at least one output through which the power supply unit is connectable to at least one electronic control unit of the automation system. The power supply unit of the rail-mounted device is equipped to detect a voltage drop or a loss of voltage at the input of the power supply unit and to provide a supply voltage at a minimum of one output of the power supply unit over a limited period by means of the electrical energy stored in the energy storage device. The rail-mounted device has at least one signal output for indicating a voltage drop or voltage loss detected at the input of the power supply unit.

Claims

1. A rail-mounted device for an automation system, the rail-mounted device comprising: at least one local bus interface to connect the rail-mounted device to a local bus of an automation system; and a power supply unit that comprises at least one input to connect the rail-mounted device to a voltage source and at least one output through which the power supply unit is connectable to at least one electronic control unit of the automation system to provide a supply voltage, wherein the power supply unit of the rail-mounted device includes or is connectable to an energy storage device for storing electrical energy, wherein the power supply unit of the rail-mounted device detects a voltage drop or a loss of voltage at the input of the power supply unit and provides a supply voltage at a minimum at one output of the power supply unit over a limited period via the electrical energy stored in the energy storage device, and wherein the rail-mounted device has at least one signal output to indicate a voltage drop or voltage loss detected at the input of the power supply unit.

2. The rail-mounted device according to claim 1, wherein the rail-mounted device is a head station with the electronic control unit or a terminal block that is distinct from a head station.

3. The rail-mounted device according to claim 1, wherein the rail-mounted device has a shutoff device that is equipped to interrupt the supply of power to one or more local bus nodes connected to the local bus if the power supply unit of the rail-mounted device detects a voltage drop or a loss of voltage at the input of the power supply unit.

4. The rail-mounted device according to claim 3, wherein the shutoff device is equipped to interrupt the supply of power to the downstream local bus nodes of the local bus.

5. The rail-mounted device according to claim 3, wherein the shutoff device for terminating the local bus in the event of a detected voltage drop or voltage loss is designed in such a manner that the communication of process data through the local bus continues to be possible.

6. A head station for an automation system, the head station comprising: an electronic control unit that is designed to carry out control tasks of the automation system; at least one local bus interface to connect the head station to a local bus of an automation system; and a power supply unit that has at least one input to connect the head station to a voltage source, wherein the head station has a signal input through which a detected voltage drop or voltage loss of the supply voltage is indicated to the head station, and wherein the electronic control unit of the head station executes an emergency program in order to transfer the head station into a safe state in an event of a voltage drop or voltage loss indicated through the signal input.

7. The head station according to claim 6, wherein the head station obtains at least some data from local bus nodes connected to the local bus after the indication of a voltage drop or voltage loss.

8. An automation system for process automation, the automation system comprising: at least one head station according to claim 6; and at least one rail-mounted device, wherein the head station and the rail-mounted device are connected to a common local bus through their respective local bus interfaces, wherein an output of a power supply unit of the rail-mounted device is connected to an input of the power supply unit of the head station, wherein at least one signal output to indicate a voltage drop or voltage loss detected at the input of the power supply unit of the rail-mounted device is connected to the signal input to indicate a voltage drop or voltage loss.

9. The automation system according to claim 8, wherein additional terminal blocks, which are connected to a common local bus through a respective local bus interface, are provided downstream of the rail-mounted device starting from the head station, and wherein the rail-mounted device is equipped via a shutoff device to interrupt one or more bus nodes connected to the local bus if the power supply unit of the rail-mounted device detects a voltage drop or a loss of voltage at the input of the power supply unit.

10. The automation system according to claim 9, wherein the rail-mounted device is equipped via the shutoff device to interrupt the supply of power to all downstream local bus nodes of the local bus.

11. A method for process automation via an automation system, wherein the automation system comprises a head station, a voltage-buffered rail-mounted device, and one or more additional rail-mounted devices, which are connected to one another via a common local bus, the method comprising: detecting a voltage drop or voltage loss at an input of a power supply unit of the voltage-buffered rail-mounted device with which the rail-mounted device is connected to a voltage source; providing an electrical supply voltage at an output of the power supply unit of the voltage-buffered rail-mounted device from an electrical energy storage device, the output of the power supply unit of the voltage-buffered rail-mounted device being connected to an input of a power supply unit of the head station; indicating the detected voltage drop or voltage loss at a minimum of one signal output of the voltage-buffered rail-mounted device, the signal output of the voltage-buffered rail-mounted device being connected to a signal input of the head station; and executing an emergency program by an electronic control unit of the head station when a detected voltage drop or voltage loss at the signal input of the head station has been indicated by the voltage-buffered rail-mounted device, while the head station is powered with the provided electrical supply voltage through the input of the power supply unit of the head station.

12. The method according to claim 11, wherein the supply of power to one or more bus nodes connected to the local bus is interrupted via a shutoff device of the voltage-buffered rail-mounted device after the detection of a voltage drop or voltage loss.

13. The method according to claim 12, wherein the supply of power to downstream local bus nodes of the local bus is interrupted.

14. The method according to claim 12, wherein the local bus is terminated via a shutoff device of the voltage-buffered rail-mounted device after the detection of a voltage drop or voltage loss so that the communication of process data through the local bus continues to be possible.

15. The method according to claim 11, wherein at least some data from local bus nodes linked and connected to the local bus are transmitted to the head station after the indication of a detected voltage drop or voltage loss at the signal input of the head station.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:

[0043] FIG. 1 is a representation of a voltage-buffered rail-mounted device in a top view;

[0044] FIG. 2 is a schematic representation of the voltage-buffered rail-mounted device; and

[0045] FIG. 3 is a representation of an automation system with a voltage-buffered rail-mounted device in a wiring example.

DETAILED DESCRIPTION

[0046] FIG. 1 shows a voltage-buffered rail-mounted device 10 (also referred to as voltage-buffered supply terminal) in the form of a terminal block, wherein the rail-mounted device 10 has a housing 11 on which a multiplicity of terminals are provided, wherein the housing 11 has a connecting mechanism on a rear side in order to be able to attach the rail-mounted device 10 to a DIN rail, for example. A local bus interface 12 can be located on each of the two sides of the housing 11 that extend laterally from the visible front side in the plane of view in order to be able to connect the rail-mounted device 10 to a local bus of an automation system. In particular, the local bus interface 12 provided on the right side of the housing can be designed in this case such that the devices connected thereto through the local bus can be switched off, as explained later.

[0047] The rail-mounted device 10 additionally has an input 13 of a power supply unit that is arranged in the interior of the housing 11 and is not visible, which input is designed in the form of two conductor entry openings in the exemplary embodiment from FIG. 1. With the aid of these two conductor entry openings of the input 13, the rail-mounted device can be connected to an external voltage source in order to thus supply the rail-mounted device with electrical energy through the external voltage source.

[0048] In addition, multiple outputs 14a to 14c of the power supply unit of the rail-mounted device 10 are provided, each of which can be designed in the form of a conductor entry opening. The voltage-buffered rail-mounted device 10 provides an electrical supply voltage at these outputs 14a to 14c in order to thus supply the loads connected to the outputs 14a to 14c with electrical energy. In this case, the output 14a can be unbuffered, for example, which is to say no electrical supply voltage would be provided for emergency operation at this output 14a in the event of a voltage drop and voltage loss. The outputs 14b and 14c, moreover, can be buffered outputs that still provide voltage for a limited period even in the case of a voltage drop or voltage loss.

[0049] If a voltage drop or voltage loss is now detected at the input 13 of the power supply unit by the rail-mounted device 10, then the rail-mounted device 10 switches from a normal supply mode to a bridging mode in which the electrical supply voltage that is provided at the outputs 14b and 14c for a limited period is fed from an electrical energy storage device of the rail-mounted device 10. The electrical energy storage device in this case can be arranged inside the housing 11 of the rail-mounted device or be appropriately connected to such a device. The limited period within which the electrical supply voltage can still be provided at the outputs 14b and 14c in bridging mode depends here on the capacity of the energy storage device and the loads to be supplied in bridging mode.

[0050] In addition, the rail-mounted device 10 has a signal output 15 at which an electrical signal is output in order to appropriately indicate a voltage drop or voltage loss and thus inform a connected load that the outputs 14b and 14c are now powered from the electrical energy storage device and the rail-mounted device is consequently working in bridging mode. In the simplest case, it is possible here that the signal output is an NO output (Normally Open output), which is closed by means of a relay in normal supply mode, wherein the presence of an external voltage source is an essential prerequisite for the closing of the relay. As a result, a control voltage is continuously present at the signal output 15 in normal supply mode, indicating that everything is in order.

[0051] If the rail-mounted device 10 changes from normal supply mode to bridging mode, then the relay lacks a necessary supply voltage so that the signal output 15 switches to the open state. Control voltage is therefore no longer present at the signal output 15, which can be interpreted by the relevant load to mean that the voltage-buffered supply terminal 10 has switched to bridging mode.

[0052] It is also possible, however, that digital signals are transmitted through the signal output 15 on the basis of an appropriate protocol, by which means still more information concerning the voltage drop or voltage loss can be transmitted to the desired load.

[0053] Alternatively or in addition, it is also possible, however, that the indicating takes place through the local bus interface 12 on the local bus so that a device connected to the local bus, such as a head station, gets an indication through the local bus of the voltage drop or voltage loss. This is especially advantageous when the head station has no corresponding additional signal input for indicating the voltage drop or voltage loss, for example.

[0054] In addition, the rail-mounted device can also have field supply terminals 16 in order to be able to connect field devices such as sensors or actuators, for example. The field supply terminals can be configured or used as inputs or outputs. The electric potential is usually forwarded through the adjacent blade contacts 17 to the downstream terminals (which are arranged on the right, next to the rail-mounted device 10). In this case, one of the conductor contacts, for example the second conductor contact in each case, can also be used as an output.

[0055] FIG. 2 shows the schematic structure of the rail-mounted device 10. The power supply unit 20, which is located inside the housing of the rail-mounted device 10 in the exemplary embodiment, has the components already known from FIG. 1 such as input 13 for connecting the rail-mounted device 10 to an external energy source, outputs 14 for supplying loads connected to the rail-mounted device 10, as well as a signal output 15 for indicating a voltage drop or voltage loss. The power supply unit 20 additionally has a control module 21, which is designed to detect a voltage drop or voltage loss at the input 13 of the power supply unit 20 and, moreover, is equipped so as to switch the rail-mounted device 10 from normal supply mode to bridging mode and back. In normal supply mode, the supply of the outputs 14a, 14b, and 14c is implemented by the control module 21 through the external energy source connected to the input 13 of the power supply unit 20. In bridging mode, in contrast, the supply of the buffered outputs 14b and 14c is fed by the electrical energy stored in the electrical energy storage device 22, wherein a corresponding signal is simultaneously provided at the signal output 15 by the control module 21 in order to indicate the change from normal supply mode to bridging mode to units connected to this signal output 15.

[0056] The control module 21 is additionally in signal connection with a shutoff device or a shutoff module 30, wherein the shutoff device or the shutoff module 30 is connected to the control logic of the local bus interface 12. Through the local bus interface 12, additional terminal blocks can be connected to the voltage-buffered supply terminal 10, which is designed strictly as a built-in unit, so that they can be connected through this local bus interface 12 to the local bus provided by the head station of the automation system (see FIG. 3).

[0057] In the exemplary embodiment from FIG. 2, the shutoff device 30 is designed such that it manipulates the local bus interface 12 on the right side of the housing of the rail-mounted device 10 in such a manner that the terminal blocks connected to the local bus on the right side of the rail-mounted device 10 are disconnected from the local bus. This has the advantage that additional loads that are supplied with electrical energy through the local bus are switched off so that the electrical energy stored in the energy storage device 22 can be used for the emergency program of the head station and thus correspondingly for the essential functions in bridging mode. If applicable, selected upstream local bus nodes can also continue to be supplied with the electrical energy stored in the energy storage device 22, for example for the purpose of executing an emergency program.

[0058] In the exemplary embodiment from FIG. 2, only the right-hand local bus interface 12 is manipulated in this case so that it can be determined, on the basis of the position where the rail-mounted device 10 is installed within the automation system as a whole, which terminal blocks connected to the local bus ultimately should still be supplied with electrical energy even in bridging mode and which terminal blocks will be taken off the network in the event of a voltage drop or voltage loss. It is possible in this case that the shutoff device likewise disconnects at least one of the field supply outputs 16 and/or the blade contacts 17 (FIG. 1) from the electrical power supply. It is likewise possible in this case for it to be selectable in advance which field supply outputs or blade contacts are disconnected from the power supply in bridging mode and which continue to be supplied with power.

[0059] It is accordingly advantageous and encompassed by the core concept of the present invention for the shutoff device to be designed such that terminal blocks connected to a first interface remain connected to the local bus while terminal blocks connected to a second local bus interface are disconnected from the local bus when a voltage drop or voltage loss is detected.

[0060] FIG. 3 shows a wiring example of an automation system 100, which has a head station 50, a rail-mounted device 10 as voltage-buffered supply terminal, as well as additional terminal blocks 60. For better understanding, the essential components—head station 50, rail-mounted device 10, as well as additional terminal blocks 60—are represented as distinct from one another, wherein they are adjacent to one another in operation so that each terminal block or each rail-mounted device 10 and 60 is connected to the local bus provided by the head station 50.

[0061] The rail-mounted device 10 now is initially connected to an external energy source 70 so that a corresponding external supply of power is provided to the rail-mounted device 10 by this means. Schematically indicated in FIG. 3 are corresponding field devices 80, such as, e.g., actuators or sensors, connected to the field supply terminals 16 of the rail-mounted device 10.

[0062] The power supply for the head station 50 is now connected to the voltage-buffered output 14b of the rail-mounted device 10 so that the output 14b of the voltage-buffered supply terminal 10 terminates in the input 51 of the head station for the supply of power to the head station. Consequently, the head station 50 is supplied with electrical energy through its input 51 by means of this voltage-buffered output 14b of the rail-mounted device 10.

[0063] In addition, the head station 50 has a signal input 52, which is connected to the signal output 15 of the rail-mounted device 10. Furthermore, the head station 50 has a local bus interface 53 with which a local bus can be provided or with which the head station can be connected to a local bus.

[0064] In normal supply mode, the head station 50 is supplied through its input 51 with electrical energy based on the external energy source 70. If a voltage drop or a voltage loss of the external energy source 70 is detected by the rail-mounted device 10, however, then the rail-mounted device 10 switches from normal supply mode to bridging mode, in which the supply of power provided at the output 14b is implemented by the energy storage device 22 (FIG. 2). In bridging mode, furthermore, a corresponding signal is provided at the signal output 15 of the rail-mounted device 10, which is received or can be detected through the signal input 52 of the head station 50, so that the head station 50 gets an indication of the switch of the rail-mounted device 10 from normal supply mode to bridging mode.

[0065] The indicating can also take place through the local bus, however. The voltage-buffered rail-mounted device 10 sends a corresponding signal through the local bus by means of its local bus interface 12 as signal output. The head station 50 receives the signal from the local bus by means of its local bus interface 53 and carries out the necessary actions.

[0066] The head station 50 is now designed such that it executes a corresponding emergency program upon indication of a bridging mode in order to persistently store data that have not yet been saved, if applicable retrieves data from other connected devices, and possibly also shuts down the operating system in order to transfer the entire automation system 100 into a safe operating state.

[0067] The rail-mounted device 10 is additionally designed such that the additional terminal blocks located to the right of the rail-mounted device 10 are disconnected from the local bus, as a result of which the supply of power to the additional terminal blocks 60 through the local bus usually is interrupted as well. Moreover, the rail-mounted device can be designed such that the terminal blocks located between the head station 50 and the rail-mounted device 10 are not disconnected from the local bus and continue to be supplied with electrical energy by the head station 50 through the local bus, so that it can be determined, on the basis of the position where the rail-mounted device 10 is installed within the automation system 100, which additional local bus nodes of the automation system 100 are still to be supplied with electrical energy in bridging mode and which are not.

[0068] The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims.