JP2022125558A - Control system and function unit - Google Patents

Abstract

To suppress rush current in activating a control system having a plurality of function units.SOLUTION: A control system (1A) includes a plurality of function units (101, 201A to 201D), and a power supply line (11). The plurality of function units (101, 201A to 201D) include power supply circuits (14A, 24A to 24D) for generating an internal power supply voltage from a power supply voltage supplied to the power supply line (11), capacitors (15A, 25A to 25D) connected to inputs of the power supply circuits (14A, 24A to 24D), and starting circuits (17A, 27A to 27D) configured so as to sequentially supply a power supply voltage with a time difference to the power supply circuits (14A, 24A to 24D) of the plurality of function units (101, 201A to 201D) in supplying power to the control system (1A), respectively.SELECTED DRAWING: Figure 2

Description

The present invention relates to a control device and functional units that constitute the control device.

When an electrical device is powered on, a current that greatly exceeds the steady-state current may temporarily flow. Such current is commonly called inrush current.

Various circuits have been proposed to suppress the inrush current. For example, Japanese Patent Application Laid-Open No. 2018-148511 (Patent Document 1) proposes an inrush current suppression circuit capable of achieving the effect of suppressing inrush current regardless of the temperature of the surrounding environment.

JP 2018-148511 A

Machines and equipment used in production sites using FA (Factory Automation) are typically controlled by control devices such as programmable logic controllers (hereinafter also referred to as "PLC"). A PLC (programmable controller) typically includes a CPU (Central Processing Unit) unit that executes various programs including a control program, and an I/O (Input/Output) unit that exchanges signals from the field. includes functional units responsible for the processing of

The power consumed by a unit generally increases as its function (which may be translated as performance) improves. Furthermore, the current consumption of the entire PLC increases as the number of units increases. Therefore, the capacity of the power supply that supplies power to the control device is determined in consideration of the power consumption of each unit and the maximum number of units included in the PLC.

However, in general, the higher the capacity of the power supply, the higher the cost for designing and manufacturing the power supply. In addition, the large capacity of the power supply causes a large inrush current when the power supply to the control apparatus is turned on.

One object of the present invention is to provide a technique for suppressing an inrush current when starting a control system having a plurality of functional units.

A control system according to an example of the present disclosure is a control system for executing a control process on a controlled object, and includes a plurality of functional units equipped with a function for executing the control process, and a power supply voltage for the plurality of functional units. and a power supply line for supplying Each of the plurality of functional units includes a power supply circuit for generating an internal power supply voltage from the power supply voltage supplied to the power supply line, and a capacitor connected to the input of the power supply circuit. The control system further includes a startup circuit configured to sequentially supply power supply voltages to the power supply circuits of the plurality of functional units with time lags when power is applied to the control system.

According to this configuration, it is possible to suppress an inrush current at the start-up of a control system having a plurality of functional units. A plurality of functional units are sequentially activated with a time lag. In each functional unit, an inrush current occurs due to charging of an input capacitor or the like. Although the rush current occurs a number of times corresponding to the number of units, the magnitude of the rush current generated at one time can be suppressed to the magnitude of the rush current generated in one functional unit.

A functional unit according to an example of the present disclosure is a functional unit that is implemented with a function for executing control processing for a controlled object and that constitutes a control system, and includes: a power supply line for applying a power supply voltage to the functional unit; and a power supply input terminal connected to a first end of the power supply line to receive a power supply voltage, and a second end of the power supply line connected to a power supply input terminal of a subsequent unit that forms a control system together with the functional unit. a power supply output terminal, a first power supply circuit for generating an internal power supply voltage from the power supply voltage supplied to the power supply line, a capacitor connected to the input of the first power supply circuit, and the internal power supply voltage When the power supply voltage is input to the internal circuit that receives the signal and executes the function, the power supply voltage is first supplied to the first power supply circuit of the functional unit when the power supply voltage is input to the power supply input terminal, and the power supply voltage is supplied to the first power supply circuit of the subsequent unit with a time lag. a start-up circuit configured to supply a power supply voltage to the power supply circuit of the.

According to this configuration, it is possible to suppress an inrush current when the control system is started. A power supply voltage is supplied to the functional unit to activate it. Then, that functional unit applies the power supply voltage to the subsequent functional unit. Therefore, although an inrush current is generated when each functional unit is activated, the magnitude of the inrush current generated at one time can be suppressed to the magnitude of the inrush current generated in one functional unit.

The activation circuit includes a connecting portion configured to switch whether or not to electrically connect the input of the first power supply circuit to the power supply line, a control circuit for controlling the connection portion, and a power supply line connected to the starting circuit. , and a second power supply circuit for supplying an operating voltage to the control circuit for operation of the control circuit. After the connection part of the functional unit electrically connects the input of the first power supply circuit to the power supply line, the functional unit instructs the control circuit of the subsequent unit to activate the connection part so as to operate the connection part. An activation signal generation circuit for generating an activation signal for instructing, and a signal output terminal for outputting the activation signal from the activation signal generation circuit to a subsequent unit can be further provided.

According to this configuration, the front-stage functional unit controls the supply of the power supply voltage to the rear-stage functional unit. Therefore, it is possible to start supplying the power supply voltage to the functional unit in the subsequent stage after starting to supply the power supply voltage to the functional unit in the preceding stage. Note that the connecting portion may be any circuit as long as it enables electrical continuity between the input of the first power supply circuit and the power supply line.

The connecting part may be a switch provided between the power supply line and the input of the first power supply circuit. The first power supply circuit may include an activation signal generation circuit. The start-up signal generation circuit may generate the start-up signal after a start-up time elapses from when the switch is turned on.

According to this configuration, the first power supply circuit of the functional unit in the preceding stage sends the activation signal to the functional unit in the succeeding stage. Controls supply of power supply voltage. Therefore, after the first power supply circuit of the preceding functional unit is activated (for example, after charging of the capacitor is completed), supply of power supply voltage to the succeeding functional unit can be started. Note that the start-up time may be the time until the input voltage of the first power supply circuit reaches a predetermined voltage. Alternatively, the activation time may be a fixed time.

The functional units and subsequent units have address values for addressing the functional units and subsequent units relative to the frontmost unit in the control system. When the address value is given, the control circuit may calculate a waiting time until activation of the connection unit, and activate the connection unit after the standby time has elapsed. The control circuit can include an activation signal generation circuit. The activation signal generation circuit generates an address value to be assigned to a subsequent unit based on the address value of the functional unit, and generates a signal indicating the address value of the subsequent unit as an activation signal.

According to this configuration, the control circuit of the functional unit in the preceding stage sends an activation signal to the functional unit in the succeeding stage. The activation signal is an address value for identifying each functional unit. The address value may be determined according to the connection position of each functional unit in the control system. Since the address value differs for each functional unit, each functional unit activates the first power supply circuit at different timings. Therefore, the timing to start supplying the power supply voltage can be made different between the preceding functional unit and the succeeding functional unit.

The input of the first power supply circuit may be connected to the power supply line. The activation circuit includes a switch provided between the input of the first power supply circuit and the power output terminal on the power supply line, a control circuit for controlling the switch to turn on the switch in accordance with the activation signal, and the power supply line. and a second power supply circuit connected to the control circuit for supplying an operating voltage to the control circuit for operation of the control circuit. The first power supply circuit may include an activation signal generation circuit that generates an activation signal when the activation time elapses from the start of supply of the power supply voltage to the first power supply circuit.

According to this configuration, by turning on the switch of the first power supply circuit of each functional unit, the power supply voltage is supplied to the next-stage functional unit. The timing of starting the supply of the power supply voltage can be made different between the preceding functional unit and the succeeding functional unit.

The input voltage of the first power supply circuit may be a voltage higher than the power supply voltage. The connection unit may include a third power supply circuit activated by the activation signal to convert the power supply voltage to the input voltage of the first power supply circuit and charge the capacitor.

The input voltage of the first power supply circuit is higher than the power supply voltage, and the functional unit is activated by the activation signal to convert the power supply voltage to the input voltage of the first power supply circuit and charge the capacitor. 3 power supply circuits may be further provided. That is, the functional unit may have a third power supply circuit in addition to the connection between the power supply line and the input of the first power supply circuit.

According to this configuration, the capacitor can be charged by the circuit that holds the input voltage of the capacitor. When the power supply to the control system is turned off, no power supply voltage is supplied to the power supply line. However, by using the power stored in the capacitor, the circuitry within the functional unit can perform the necessary processing when the power is off.

According to the present invention, it is possible to suppress an inrush current at the start of a control system having a plurality of functional units.

1 is a schematic diagram of a production system including a control system according to one embodiment; FIG. FIG. 2 is a block diagram showing a configuration related to power supply of the control system according to the present embodiment; FIG. FIG. 4 is a circuit diagram when the number of functional units to which power supply voltage is supplied is one; 4 is a diagram showing changes in current in the functional unit shown in FIG. 3; FIG. FIG. 3 is a diagram showing a configuration example in which a power supply voltage is supplied from one power supply unit to a plurality of functional units; 6 is a diagram for explaining a modification of the circuit configuration shown in FIG. 5; FIG. FIG. 7 is a diagram showing changes in current in the entire functional unit shown in FIG. 6; 3 is a diagram showing the configuration of functional units according to the first embodiment; FIG. FIG. 10 is a diagram showing a configuration of functional units according to the second embodiment; FIG. FIG. 12 is a diagram showing the configuration of functional units according to the third embodiment; FIG. 11 is a diagram showing a configuration of a modification of functional units according to the third embodiment; It is a diagram showing the configuration of a functional unit according to the fourth embodiment. It is a diagram showing another configuration of the functional unit according to the fourth embodiment. FIG. 14 is a diagram showing still another configuration of functional units according to the fourth embodiment; FIG. 14 is a diagram showing still another configuration of functional units according to the fourth embodiment;

Embodiments of the present invention will be described in detail with reference to the drawings. The same or corresponding parts in the drawings are denoted by the same reference numerals, and the description thereof will not be repeated.

<A. Application example>
First, an example of a scene to which the present invention is applied will be described. FIG. 1 is a schematic diagram of a production system including a control system according to one embodiment. A control system according to the present embodiment is provided, for example, in a FA (Factory Automation) production line 10 to control a control target. The production line 10 includes control systems 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H. The control systems 1A-1H are realized by PLC, for example.

The control systems 1A-1H are connected to a communication device 4. FIG. The control systems 1A-1H can exchange data with each other via the communication device 4. FIG. The communication device 4 is a device for realizing real-time performance required for communication performed in the industrial field, and is, for example, a switch complying with IEEE 802.1.TSN. Also, the control systems 1A, 1B, 1C, 1D, 1E, 1F, 1G, and 1H are synchronized with each other. For this purpose, each of control systems 1A, 1B, 1C, 1D, 1E, 1F, 1G, and 1H has a timer function.

In the production line 10 shown in FIG. 1, at least one of the control systems 1A to 1H is the control system according to the embodiment. Hereinafter, a control system 1A will be described as a control system according to the embodiment. All of the control systems 1A to 1H may correspond to the control system according to this embodiment. Additionally, FIG. 1 is not intended to limit the number of control systems included in production line 10 .

The control system 1A executes control processing for the field device 5 to be controlled. The control system 1A includes a plurality of functional units in which functions for executing the control processing are implemented. As shown in FIG. 1, the control system 1A includes a CPU unit 101, functional units 201A, 201B, 201C, 201D and an I/O unit 300A. The type of field device 5 is not particularly limited, and may include, for example, a servomotor. The I/O unit 300A exchanges data with the CPU unit 101 according to an industrial network protocol such as the EtherCAT (registered trademark) protocol.

Functions implemented by each of the functional units 201A, 201B, 201C, and 201D are not particularly limited. For example, functional units 201A, 201B, 201C, 201D may include communication units. In the example shown in FIG. 1, functional unit 201D is a communication unit and is connected to communication device 4 via a network.

The AC-DC power supply 400A converts an AC voltage into a DC voltage and supplies the DC voltage to the control system 1A as a power supply voltage. The power supply voltage of the control system 1A is, for example, DC24V.

CPU unit 101 and functional units 201A, 201B, 201C and 201D are coupled. This forms an internal bus (not shown) common to each unit. This internal bus includes a power supply line. In this embodiment, a power supply voltage is supplied to each of CPU unit 101 and functional units 201A-201D via a power supply line (not shown) inside control system 1A. That is, CPU unit 101 and functional units 201A-201D are connected in parallel to the power line.

Control system 1B includes CPU unit 102, functional unit 202A and I/O unit 300B. Like I/O unit 300A, I/O unit 300B communicates data with CPU unit 102 according to a protocol for industrial networks, such as the EtherCAT® protocol. Functional unit 202A is, for example, a communication unit and is connected to communication device 4 via a network. Similar to control system 1A, AC-DC power supply 400B supplies power supply voltage (eg, 24V DC) to each functional unit of control system 1B.

<B. Schematic Configuration of Control System and Functional Unit>
FIG. 2 is a block diagram showing a configuration related to power supply of the control system according to this embodiment. As shown in FIG. 2, the control system 1A includes a plurality of functional units (CPU unit 101 and functional units 201A to 201D) in which functions for executing control processing for a controlled object are implemented, and a power source for the plurality of functional units. and a power supply line 11 for supplying voltage. Each of the plurality of functional units includes a power supply circuit (power supply circuits 14A, 24A to 24D) that generates an internal power supply voltage from the power supply voltage supplied to the power supply line 11, and a capacitor (capacitor 15A, 25A-25D). The control system 1A further includes startup circuits 17A, 27A to 27D configured to sequentially supply power supply voltages to the power supply circuits of the plurality of functional units with time lags when the control system 1A is powered on.

The activation circuits 17A, 27A-27D control the power supply circuits 14A, 24A-24D so that power supply voltages are supplied in the order of the CPU unit 101, functional unit 201A, functional unit 201B, functional unit 201C, and functional unit 201D. In this specification, of the plurality of connected functional units, the functional unit to which the power supply voltage is supplied first is referred to as the "previous unit", and the functional unit to which the power supply voltage is supplied later is referred to as the "subsequent unit". unit of The CPU unit 101 corresponds to the "frontmost unit" of the plurality of functional units within the control system 1A, and the functional unit 201D corresponds to the "lastmost functional unit" of the plurality of functional units within the control system 1A. .

As shown in FIG. 2, the basic circuit configuration for supplying power supply voltage is the same between CPU unit 101 and functional units 201A-201D. CPU unit 101 and functional units 201A-201D include power supply lines 11A, 21A-21D, power input terminals 12A, 22A-22D, and power output terminals 13A, 23A-23D, respectively.

The power supply lines 11A, 21A-21D are power supply lines for applying power supply voltages to the CPU unit 101 and the functional units 201A-201D, respectively. Power supply input terminals 12A, 22A-22D are connected to first ends of power supply lines 11A, 21A-21D, respectively, to receive power supply voltage. The power output terminals 13A, 23A to 23D are connected to the second ends of the power lines 11A, 21A to 21D, respectively, and are configured to be connectable to power input terminals of subsequent units.

By connecting the CPU unit 101 and the functional units 201A to 201D, the power supply output terminal of the functional unit is connected to the power supply input terminal of the unit immediately following that unit. As a result, the power lines 11A and 21A to 21D are connected to form the power line 11. FIG. Power input terminal 12A of CPU unit 101 is coupled to AC-DC power supply 400A to receive a power supply voltage (eg, 24V DC). Thus, each of CPU unit 101 and functional units 201A-201D receives power supply voltage through power supply line 11. FIG.

The CPU unit 101 and the functional units 201A to 201D respectively include power supply circuits 14A, 24A to 24D, capacitors 15A, 25A to 25D, internal circuits 16A, 26A to 26D, and starter circuits 17A, 27A to 27D. . The power supply circuits 14A, 24A to 24D (first power supply circuits) generate internal power supply voltages from the power supply voltages supplied to the power supply lines 11A, 21A to 21D, respectively. The internal power supply voltage is, for example, DC5V, DC3.3V, or the like.

Capacitors 15A, 25A-25D are connected to inputs of power supply circuits 14A, 24A-24D, respectively.

The internal circuits 16A, 26A-26D receive the internal power supply voltage and perform functions for control processing by the control system 1A. Each of the starter circuits 17A, 27A to 27D first supplies the power supply voltage to the internal power supply circuit of the functional unit containing the starter circuit when the power supply voltage is input to the power supply input terminal, and the starter circuit 17A, 27A to 27D first supplies the power supply voltage to the internal power supply circuit of the functional unit including the starter circuit with a time lag. It is configured to supply the power supply voltage to the internal power supply circuit of the subsequent unit. In one embodiment, the activation circuit sends a signal to the activation circuit of the subsequent unit to activate the power supply circuit. In another embodiment, after the power circuit of the preceding functional unit wakes up, it sends a signal to the wake-up circuit of the succeeding unit to wake up the power circuit.

According to the present embodiment, power supply voltages are sequentially supplied to power supply circuits of a plurality of functional units with a time lag. As a result, it is possible to suppress an increase in the capacity of the power supply device while suppressing an inrush current at the time of starting a control system having a plurality of units. This point will be described below.

<C. Issues Concerning Suppression of Inrush Current>
FIG. 3 is a circuit diagram when the number of functional units supplied with power supply voltage is one. 3 shows a configuration related to the power supply circuit of the CPU unit 101. As shown in FIG. The AC-DC power supply 401 supplies a power supply voltage (for example, 24V DC) to the power supply circuit 14A.

FIG. 4 is a diagram showing current changes in the functional unit shown in FIG. When the functional unit is powered on (Power ON), the current i rises sharply and reaches a value (X[A]) larger than the steady-state value. A current that suddenly rises when the power is turned on is called an inrush current. As the capacitor 15A is charged, the current i gradually decreases and reaches the normal operating current value (Y[A]) of the functional unit.

One factor that causes the inrush current is the charging of the capacitor 15A connected to the input of the power supply circuit 14A. A capacitor 15A having a large capacity is connected to the power supply circuit 14A. When power is applied to the functional unit, a large current momentarily flows to charge the large-capacity capacitor. Therefore, an inrush current is generated.

The reason why a large-capacity capacitor is used for the capacitor 15A is as follows. In a functional unit with high functionality (which may be called high performance) such as a CPU unit, power consumption per unit is large because the power consumption of the CPU or peripheral circuits in the unit is large. Furthermore, high-performance (high-performance) units require preparations for power-off, such as data protection processing, when the power is turned off. Alternatively, it is necessary to follow the power-off order inside the functional units so as not to damage the CPU and peripheral circuits when powering off. Therefore, when the power is turned off, it is necessary to hold the power inside the functional unit for a certain period of time. In order to meet this demand, it is necessary to store power in a capacitor having a large capacity.

FIG. 5 is a diagram showing a configuration example in which a power supply voltage is supplied from one power supply unit to a plurality of functional units. In the configuration shown in FIG. 5, power supply voltage (for example, 5V DC) is supplied from power supply unit 40 to CPU unit 101 and functional units 201A to 201C.

The power supply unit 40 includes a power supply circuit 41 , a capacitor 42 and a power supply circuit 43 . The output of power supply circuit 41 is connected to the input of capacitor 42 and power supply circuit 43 . Power supply circuit 41 is a voltage holding circuit that receives a voltage (for example, 24 VDC) from AC-DC power supply 402 and holds the input voltage of power supply circuit 43 and capacitor 42 . The power supply circuit 43 converts the input voltage into the power supply voltage of the functional unit.

In the configuration shown in FIG. 5, the output capacity of power supply unit 40 depends on the power consumption of the functional units. When the power consumption of a plurality of functional units as a whole is large (when the power consumption of a functional unit is large, when the number of functional units is increased, etc.), a power supply unit with a large output capacity is required.

Furthermore, in the configuration shown in FIG. 5, when determining the output capacity of the power supply unit 40, the maximum number of connected functional units or the maximum power consumption must be assumed in advance. However, even if the output capacity of the power supply unit 40 is determined in this way, the actual number of functional units may be significantly smaller than the maximum number of connectable units. Increasing the output capacity of the power supply unit more than necessary may cause problems in terms of manufacturing cost, size, heat dissipation, and the like.

FIG. 6 is a diagram for explaining a modification of the circuit configuration shown in FIG. In the configuration shown in FIG. 6, a plurality of functional units (CPU unit 101 and functional units 201A-201D, respectively) have power supply circuits (power supply circuits 14A, 24A-24D). The power supply circuit of each functional unit generates an internal power supply voltage from the power supply voltage (DC24V) supplied from the AC-DC power supply 400A. A capacitor (capacitors 15A, 25A to 25D) is connected to the input of the power supply circuit of each functional unit.

FIG. 7 is a diagram showing changes in current in the entire functional unit shown in FIG. A power supply voltage is simultaneously supplied to a plurality of functional units. Assuming that the capacity of the power supply circuit (including the capacity of the capacitor) is the same among the plurality of functional units, the inrush current and the current after normal startup are proportional to the number of functional units. Therefore, the inrush current and the current during normal operation are five times the inrush current (X[A]) and the current during normal operation (Y[A]) when there is one functional unit, respectively.

Due to the large difference between the inrush current and the current consumption (or power consumption) during normal operation, it becomes difficult to select, for example, the power supply or parts such as breakers, fuses, and filters installed between the power supply and the control system. . Basically, parts with large capacities are selected for parts such as power supplies and breakers. However, the higher the capacity, the more expensive the power supply and components. Furthermore, if the capacity of the breaker and fuse is determined considering the inrush current, even if a current larger than the normal current is generated during operation, if the current is smaller than the inrush current, the breaker or fuse will not function. . This poses a problem in terms of circuit protection.

In order to suppress an increase in the output capacity of the power supply device, each of the plurality of functional units must have a power supply circuit. However, since a plurality of functional units that make up the control system are connected in parallel to the power supply, rush current tends to increase.

<D. Specific Configuration of Functional Unit According to Embodiment>
(Embodiment 1)
FIG. 8 is a diagram showing the configuration of functional units according to the first embodiment. As shown in FIG. 8, CPU unit 101 is connected by input lines 44 and 45 to AC-DC power supply 400A. A power supply voltage (24 DC) is supplied to the input line 44 with the voltage of the input line 45 as a reference (0 V DC).

A breaker 46 is inserted in the input lines 44 and 45 . A fuse may be inserted into input line 44 instead of breaker 46 .

In the CPU unit 101, power supply input terminals 12A and 111 are connected to input lines 44 and 45, respectively. As a result, the power supply line 11 is supplied with the power supply voltage. The power input terminal 111 is connected to a reference voltage line 112 inside the control system 1A. Reference voltage line 112 is connected to terminal 121, which is connected to terminal 221 of functional unit 201A. Terminal 221 is connected to reference voltage line 212 , which is connected to terminal 232 .

When power supply voltage is supplied to the CPU unit 101, the activation circuit 17A activates the power supply circuit 14A. The activation circuit 17A includes a switch 171, a logic circuit (Logic) 172, and a logic power supply circuit 173. FIG.

The switch 171 is a connection unit configured to switch whether or not to electrically connect the input of the power supply circuit 14A to the power supply line 11 . The switch 171 is provided between the power supply line 11 and the input of the power supply circuit 14A. As shown in FIG. 8, a resistor 151 may be arranged between the capacitor 15A and the switch 171 to suppress rush current. Resistor 151 is connected to the input of power supply circuit 14A along with capacitor 15A.

A logic circuit 172 is a control circuit that controls the switch 171 . The logic power supply circuit 173 is an operating power supply circuit (second power supply circuit) that is connected to the power supply line 11 (power supply line 11A) and supplies the logic circuit 172 with an operating voltage for operating the logic circuit 172 . The logic power supply circuit 173 supplies the logic circuit 172 with a logic circuit power supply voltage (for example, DC 5V).

Since the power supply voltage is supplied to the logic power supply circuit 173 at the same time as the control system 1A is activated, the logic circuit 172 also receives the operating voltage from the logic power supply circuit 173 immediately after the control system 1A is activated. Therefore, the logic circuit 172 is activated almost simultaneously with the activation of the control system 1A to turn on the switch 171 . Thereby, the power supply voltage is supplied to the power supply circuit 14A. A rush current is generated in the CPU unit 101 because the capacitor 15A is charged. However, no inrush current occurs in other functional units.

The power supply circuit 14A includes an activation signal generation circuit 141. FIG. The activation signal generation circuit 141 generates the activation signal SG after the switch 171 of the CPU unit 101 electrically connects the input of the power supply circuit 14A to the power supply line 11 .

The activation signal SG is a signal that notifies the functional unit 201A that charging of the capacitor 15A has been completed. For example, the activation signal generation circuit 141 may generate the activation signal SG after the activation time has elapsed since the switch 171 was turned on. This startup time may be, for example, the time until power supply circuit 14A detects that the input voltage of power supply circuit 14A has reached a preset voltage. Alternatively, the activation time may be a predetermined time from when the switch 171 is turned on. This "predetermined time" can be determined in advance based on a time constant determined by the resistance value of resistor 151 and the capacitance value of capacitor 15A.

The power supply circuit 14A (start signal generation circuit 141) outputs a start signal SG. The start signal SG is output to the outside of the CPU unit 101 from the signal output terminal 19B. A signal input terminal 29A of the functional unit 201A is connected to the signal output terminal 19B. Therefore, the activation signal SG is input to the activation circuit 27A of the functional unit 201A.

Activation circuit 27A includes switch 271 , logic circuit 272 , and logic power supply circuit 273 . The functions of the switch 271 , the logic circuit 272 and the logic power supply circuit 273 are basically the same as the functions of the switch 171 , the logic circuit 172 and the logic power supply circuit 173 . Since the power supply voltage is supplied to the logic power supply circuit 273 at the same time as the control system 1A is activated, the logic circuit 272 also receives the operating voltage from the logic power supply circuit 273 immediately after the control system 1A is activated. The logic circuit 272 turns on the switch 271 in response to the activation signal SG. As a result, the input of the power supply circuit 24A is connected to the power supply line 11, and the power supply voltage is supplied to the power supply circuit 24A. The activation signal SG from the CPU unit 101 corresponds to a signal for instructing the timing of activating (switching on) the connecting section of the functional unit 201A.

The power supply circuit 24A includes an activation signal generation circuit 241 . Similar to the start signal generation circuit 141, the start signal generation circuit 241 generates the start signal SG when charging of the capacitor 25A is completed. The power supply circuit 24A (start signal generation circuit 241) outputs the start signal SG from the signal output terminal 29B to the outside.

The signal output terminal 29B is connected to the signal input terminal of the subsequent unit (functional unit 201B). As a result, the activation signal SG from the functional unit 201A is input to the functional unit 201B. Since the operation of functional unit 201B after receiving activation signal SG is the same as that of functional unit 201A, description thereof will not be repeated.

Thus, in the first embodiment, when the charging of the capacitor in the preceding unit is completed, the preceding unit sends the starting signal SG to the succeeding unit. The activation circuit of the subsequent unit activates the power supply circuit according to the activation signal SG. Since the units in the foremost stage are activated with a time lag, the inrush current occurs the number of times corresponding to the number of units. It can be suppressed to the magnitude of the current.

(Embodiment 2)
FIG. 9 is a diagram showing the configuration of functional units according to the second embodiment. In the configuration shown in FIG. 9, the activation signal generation circuit is included in the logic circuit. The logic circuit therefore generates the activation signal SG.

Specifically, the start signal SG is a signal indicating an address value for identifying the connection position of the functional unit in the control system 1A. "Connection position" may be read as "order" or "stage". The address value of each functional unit is a relative value based on the CPU unit 101, which is the frontmost unit.

As shown in FIG. 9, the address value of the CPU unit 101 is assumed to be "00". Since the position of the CPU unit 101 in the control system 1A is predetermined, the address of the CPU unit 101 can be fixed. The logic circuit 172 of the CPU unit 101 notifies the functional unit 201A, which is a subsequent unit, of the address of the functional unit 201A.

The activation signal generation circuit 141 can be realized by an address addition circuit. The address addition circuit adds 1 to the address value "00". Therefore, the address value of functional unit 201A becomes "01". The activation signal generation circuit 141 outputs a signal notifying the address value "01" from the signal output terminal 19B as the activation signal SG. Since the signal input terminal 29A of the functional unit 201A is connected to the signal output terminal 19B, the start signal SG is input to the logic circuit 272. FIG.

The logic circuit 272 adds 1 to the address value "01" to determine the address value "02" of the functional unit 201B, and outputs a signal notifying the address value "02" as the start signal SG from the signal output terminal 29B. Output.

The logic circuit 272 determines the timing to turn on the switch 271 based on the address value "01" of the functional unit 201A. For example, the logic circuit 272 sets the standby time to a value obtained by multiplying the address value by a predetermined time constant (eg, 500 ms). The logic circuit 272 operates an internal timer to turn on the switch 271 when the set waiting time has passed.

Control of switches in functional unit 201B and subsequent functional units is similar to control of switch 271 in functional unit 201A. In the second embodiment, the preceding functional unit notifies the subsequent unit of the address of the subsequent unit. Each functional unit waits for the time corresponding to the address value and turns on the switch after the waiting time has passed. Therefore, between a certain functional unit and the subsequent functional unit, the switch-on timing differs by a time corresponding to (address increment value)×(predetermined time constant). As a result, power supply voltages can be sequentially supplied to the power supply circuits of a plurality of functional units with a time lag, so that the inrush current of the entire control system can be suppressed as in the first embodiment.

In the above-described form, the functional unit in the preceding stage generates the address value of the functional unit in the succeeding stage by increasing its own address value. However, the address value of the subsequent functional unit may be generated by subtracting the address value. In this case, the address value of the CPU unit 101 is the largest among the plurality of functional units. Between a certain functional unit and the subsequent functional unit, the switch-on timing should be different by a time corresponding to (absolute value of address decrement value)×(predetermined time constant).

(Embodiment 3)
FIG. 10 is a diagram showing the configuration of functional units according to the third embodiment. In the configuration shown in FIG. 10, the input of the power supply circuit is connected to the power supply line in each functional unit. Furthermore, a switch is provided on the power line and between the input of the power circuit and the power output terminal. Therefore, the activation circuit of each functional unit is a circuit for supplying the power supply voltage to the power supply circuit of the functional unit at the next stage of the functional circuit.

As in the first embodiment, the activation signal generation circuit is included in the power supply circuit and generates the activation signal when the charging of the capacitor is completed. In the third embodiment, the activation signal is sent to the logic circuit within the functional unit to which the activation signal generating circuit belongs. In this respect, the third embodiment differs from the first embodiment.

Specifically, in the CPU unit 101, the input of the power supply circuit 14A is connected to the power supply line 11A. A switch 171 is provided on the power line 11A and between the input of the power circuit 14A and the power output terminal 13A. Similarly, in functional unit 201A, the input of power supply circuit 24A is connected to power supply line 21A. A switch 271 is provided on the power line 21A and between the input of the power circuit 24A and the power output terminal 23A.

In the configuration shown in FIG. 10, in the CPU unit 101, the activation signal generation circuit 141 outputs the activation signal SG to the logic circuit 172 when charging of the capacitor 15A is completed. The logic circuit 172 turns on the switch 171 in response to the activation signal SG.

By turning on the switch 171, the power supply voltage is input to the functional unit 201A. Therefore, capacitor 25A is charged. When the charging of the capacitor 25A is completed, the activation signal generation circuit 241 sends the activation signal SG to the logic circuit 272. FIG. The logic circuit 272 turns on the switch 271 in response to the activation signal SG. In addition, in the third embodiment, the conditions for determining the timing of generating the activation signal may be the same as the conditions applied in the first embodiment.

Also in the third embodiment, power supply voltages can be sequentially supplied to the power supply circuits of a plurality of functional units with a time lag. Therefore, the inrush current of the entire control system can be suppressed.

In the third embodiment, both the logic power supply circuit and the power supply circuit are powered on at the same time. Therefore, the configuration shown in FIG. 11 may be employed.

FIG. 11 is a diagram showing a configuration of a modification of functional units according to the third embodiment. In the configuration shown in FIG. 11, the activation signal generation circuits 141 and 241 are omitted from the power supply circuits 14A and 24A, respectively. In this respect, the configuration shown in FIG. 11 differs from the configuration shown in FIG.

The logic circuit 172 operates an internal timer when an operating voltage is supplied from the logic power supply circuit 173 . The logic circuit 172 turns on the switch 171 when the preset waiting time has passed. As a result, both the logic power supply circuit 273 and the power supply circuit 24A of the functional unit 201A are powered on at the same time.

The logic circuit 272 operates an internal timer when an operating voltage is supplied from the logic power supply circuit 273 . The logic circuit 272 turns on the switch 271 when the preset waiting time has passed. The same operation as the operation described above is sequentially executed in units subsequent to the functional unit 201A. Therefore, power supply voltages are sequentially supplied to power supply circuits of a plurality of functional units with a time lag.

(Embodiment 4)
The activation methods of the functional units according to the first to third embodiments can also be applied to a functional unit having a holding power supply generation circuit (third power supply circuit). The holding power supply generation circuit is a circuit for holding the input voltage of the capacitor connected to the input of the power supply circuit (thus holding the power stored in the capacitor). Predetermined processing such as data protection can be executed when the functional unit is powered off by providing the holding power source generation circuit. Alternatively, the CPU and peripheral circuits can be powered off according to a predetermined order. Thereby, the parts inside the functional unit can be protected.

FIG. 12 is a diagram showing the configuration of functional units according to the fourth embodiment. As shown in FIG. 12, the CPU unit 101 includes a holding power supply generation circuit 18 . Holding power supply generation circuit 18 is connected to power supply line 11A via resistor 151 and receives a power supply voltage (eg, 24 VDC). The holding power supply generation circuit 18 converts the power supply voltage into the input voltage of the power supply circuit 14A and charges the capacitor 15A (charge holding capacitor) connected to the input of the power supply circuit 14A. The input voltage of the power supply circuit 14A is a voltage higher than the power supply voltage, for example DC50V. The power supply circuit 14A generates a power supply voltage (for example, 5V DC) for internal circuits from the output voltage (50V DC) of the holding power supply generation circuit 18 .

The holding power generation circuit 18 is activated by the logic circuit 172 . When the holding power generation circuit 18 is activated, the holding power generation circuit 18 converts the power supply voltage on the power supply line 11A to the input voltage of the power supply circuit 14A and charges the capacitor 15A.

When the charging of the capacitor 15A is completed, the activation signal generation circuit 141 in the power supply circuit 14A generates the activation signal SG and outputs the activation signal SG to the signal output terminal 19B. Functional unit 201A receives activation signal SG via signal input terminal 29A. The activation signal SG is input to the logic circuit 272 . The logic circuit 272 activates the holding power supply generation circuit 28 in response to the activation signal SG.

Similarly to the holding power supply generation circuit 18, the holding power supply generation circuit 28 converts the power supply voltage on the power supply line 21A to the input voltage of the power supply circuit 24A and charges the capacitor 25A. When the charging of the capacitor 25A is completed, the activation signal generation circuit 241 in the power supply circuit 24A generates the activation signal SG for activating the holding power supply generation circuit of the subsequent unit, and outputs the activation signal SG to the signal output terminal 29B. to output

The power supply circuit 14A receives an input voltage when the holding power supply generation circuit 18 is activated. In the fourth embodiment, the holding power supply generation circuit 18 is a connection section for electrically connecting the input of the power supply circuit 14A to the power supply line 11A. Therefore, in the configuration shown in FIG. 12, the activation circuit 17A includes the holding power supply generation circuit 18 instead of the switch 171 as a connection section. Similarly, in the functional unit 201A, the activation circuit 27A includes a holding power supply generation circuit 28 as a connection section instead of the switch 271. FIG. In this point, the fourth embodiment differs from the first embodiment.

FIG. 13 is a diagram showing another configuration of functional units according to the fourth embodiment. As shown in FIG. 13, the switches in the functional units according to the second embodiment (see FIG. 9) can be replaced with holding power supply generation circuits.

FIG. 14 is a diagram showing still another configuration of functional units according to the fourth embodiment. As shown in FIG. 14, in the configuration of the functional unit according to the third embodiment (see FIG. 10), a holding power supply generating circuit may be added between the resistor and the capacitor.

FIG. 15 is a diagram showing still another configuration of functional units according to the fourth embodiment. As shown in FIG. 15, in the configuration of the functional unit according to the third embodiment (see FIG. 11), a holding power supply generating circuit may be added between the resistor and the capacitor.

11, in the functional unit shown in FIG. 15, when the operating voltage is supplied from the logic power supply circuit 173, the logic circuit 172 operates the internal timer. The logic circuit 172 turns on the switch 171 when the preset waiting time has passed. As a result, both the logic power supply circuit 273 and the power supply circuit 24A of the functional unit 201A are powered on at the same time. The logic circuit 272 operates an internal timer when an operating voltage is supplied from the logic power supply circuit 273 . The logic circuit 272 turns on the switch 271 when the preset waiting time has passed. The same operation as the operation described above is sequentially executed in units subsequent to the functional unit 201A. Therefore, power supply voltages are sequentially supplied to power supply circuits of a plurality of functional units with a time lag.

When the holding power generation circuit charges the capacitor connected to the input of the power supply circuit, a current larger than that during normal operation is generated. The operation of the functional unit according to the fourth embodiment at startup is the same as the operation of the functional unit according to the corresponding form among the first to third embodiments. Therefore, in the fourth embodiment as well, the power supply voltage is sequentially supplied to the power supply circuits of the plurality of functional units with a time lag, so that the rush current can be suppressed.

<E. Note>
The present embodiment as described above includes the following technical ideas.

[Configuration 1]
A control system (1A) for executing control processing for a controlled object,
a plurality of functional units (101, 201A to 201D) equipped with functions for executing the control process;
A power supply line (11) for supplying power supply voltage to the plurality of functional units (101, 201A to 201D),
Each of the plurality of functional units (101, 201A-201D)
a power supply circuit (14A, 24A to 24D) for generating an internal power supply voltage from the power supply voltage supplied to the power supply line (11);
a capacitor (15A, 25A-25D) connected to the input of the power supply circuit (14A, 24A-24D);
Said control system (1A) comprises:
When the power supply to the control system (1A) is turned on, the power supply voltage is sequentially supplied to the power supply circuits (14A, 24A to 24D) of the plurality of functional units (101, 201A to 201D) with a time lag. a control system (1A) further comprising a controlled activation circuit (17A, 27A-27D).

[Configuration 2]
A functional unit (101, 201A to 201D) implementing a function for executing a control process for a controlled object (5) and constituting a control system (1A),
power supply lines (11A, 21A to 21D) for applying power supply voltage to the functional units (101, 201A to 201D);
power supply input terminals (12A, 22A to 22D) connected to first ends of the power supply lines (11A, 21A to 21D) to receive the power supply voltage;
Subsequent units (201A to 201D) connected to the second ends of the power supply lines (11A, 21A to 21D) and forming the control system (1A) together with the functional units (101, 201A to 201D) power output terminals (13A, 23A to 23D) configured to be connectable to the power input terminals (22A to 22D) of
a first power supply circuit (14A, 24A-24D) for generating an internal power supply voltage from the power supply voltage supplied to the power supply line (11A, 21A-21D);
Capacitors (15A, 25A to 25D) connected to inputs of the first power supply circuit (14A, 24A to 24D);
internal circuits (16A, 26A to 26D) that receive the internal power supply voltage and perform the functions;
When the power supply voltage is input to the power supply input terminals (12A, 22A to 22D), first the first power supply circuits (14A, 24A to 24D) of the functional units (101, 201A to 201D) are supplied with the power supply voltage. A starting circuit (17A) configured to supply a power supply voltage and supply the power supply voltage to the first power supply circuits (24A to 24D) of the units (201A to 201D) at the rear stage of the unit at the rear stage with a time lag. , 27A-27D).

[Configuration 3]
The starting circuits (17A, 27A to 27D) are
Connection portions (171, 271, 28) configured to switch whether or not to electrically connect the inputs of the first power supply circuits (24A to 24D) to the power supply lines (11A, 21A to 21D). When,
a control circuit (172, 272) for controlling the connection portion (171, 271, 28);
A second power supply circuit (173, 173, 173, 173) connected to the power supply line (11A, 21A to 21D) to supply an operating voltage for operating the control circuit (172, 272) to the control circuit (172, 272) 273) and
The functional units (101, 201A-201D) are
The connecting portions (171, 271, 28) of the functional units (101, 201A to 201D) electrically connect the inputs of the first power supply circuits (24A to 24D) to the power supply lines (11A, 21A to 21D). activation for instructing the control circuit (272) of the subsequent unit of the timing to activate the connection units (171, 271, 28) so as to operate the connection units (271, 28) after connecting to a start signal generation circuit (141, 241) for generating a signal (SG);
The functional unit (101, 201A to 201D) according to configuration 2, further comprising signal output terminals (19B, 29B) for outputting the activation signal from the activation signal generation circuit (141, 241) to the subsequent unit. ).

[Configuration 4]
the connection part (171, 271) is a switch provided between the power supply line (11A, 21A to 21D) and the input of the first power supply circuit (24A to 24D),
the first power supply circuit (24A to 24D) includes the activation signal generation circuit (141, 241),
The functional unit (101, 201A-201D) according to configuration 3, wherein the start-up signal generation circuit (141, 241) generates the start-up signal (SG) after a start-up time elapses from when the switch is turned on.

[Configuration 5]
The functional units (101, 201A to 201D) and the subsequent units (201A to 201D) are based on the frontmost unit (101) in the control system (1A), and the functional units (101, 201A to 201D ) and address values for relatively addressing the subsequent units (201A-201D),
When the address value is given, the control circuit (172, 272) calculates a waiting time until the connection unit (171, 271, 28) is activated, and after the waiting time elapses, the connection unit (172, 272) 171, 271, 28),
The control circuit (172, 272) includes the activation signal generation circuit (141, 241), and the activation signal generation circuit (141, 241) responds to the address values of the functional units (101, 201A to 201D). The functional unit according to configuration 4 (101, 201A-201D).

[Configuration 6]
the inputs of the first power supply circuits (24A to 24D) are connected to the power supply lines (11A, 21A to 21D);
The starting circuit is
a switch provided between the input of the first power supply circuit (24A-24D) and the power output terminal (13A, 23A-23D) in the power supply line (11A, 21A-21D);
a control circuit (172, 272) for controlling the switch to turn on the switch in response to a start signal (SG);
A second power supply circuit (173, 173, 173, 173) connected to the power supply line (11A, 21A to 21D) to supply an operating voltage for operating the control circuit (172, 272) to the control circuit (172, 272) 273) and
The first power supply circuits (24A to 24D) are
The functional unit according to configuration 2, including a start-up signal generation circuit (141, 241) for generating the start-up signal when a start-up time elapses from the start of supply of the power supply voltage to the first power supply circuit (24A to 24D). (101, 201A-201D).

[Configuration 7]
an input voltage of the first power supply circuit (24A to 24D) is higher than the power supply voltage;
The connecting portion (171, 271, 28) is
Configuration 3, comprising a third power supply circuit (18, 28) activated by the activation signal to convert the power supply voltage into an input voltage of the first power supply circuit (24A to 24D) and charge the capacitor. 6. A functional unit (101, 201A-201D) according to any one of -5.

[Configuration 8]
an input voltage of the first power supply circuit (24A to 24D) is higher than the power supply voltage;
The functional units (101, 201A-201D) are
A configuration further comprising a third power supply circuit (18, 28) activated by the activation signal to convert the power supply voltage into an input voltage of the first power supply circuit (24A to 24D) and charge the capacitor. A functional unit (101, 201A-201D) according to 6.

It should be considered that the embodiments disclosed this time are illustrative in all respects and not restrictive. The scope of the present invention is indicated by the scope of the claims rather than the description of the above-described embodiments, and is intended to include all modifications within the scope and meaning equivalent to the scope of the claims.

1A to 1H control system 4 communication device 5 field device 10 production line 11, 11A, 21A to 21D power supply line 12A, 22A to 22D, 111 power supply input terminal 13A, 23A to 23D power supply output terminal 14A, 24A to 24D, 41, 43 power supply circuit, 15A, 25A to 25D, 42 capacitor, 16A, 24D, 26A internal circuit, 17A, 27A to 27D starting circuit, 18, 28 holding power generation circuit, 19B, 29B signal output terminal , 29A signal input terminal, 40 power supply unit, 44, 45 input line, 46 breaker, 101, 102 CPU unit, 112, 212 reference voltage line, 121, 221, 232 terminal, 141, 241 start signal generation circuit, 151 resistor, 171, 271 switch, 172, 272 logic circuit, 173, 273 logic power supply circuit, 201A to 201D, 202A function unit, 300A, 300B I/O unit, 400A, 400B, 401, 402 AC-DC power supply, SG start signal.

Claims (8)

A control system for executing control processing for a controlled object,
a plurality of functional units implemented with functions for executing the control process;
a power supply line for supplying power supply voltage to the plurality of functional units,
each of the plurality of functional units,
a power supply circuit that generates an internal power supply voltage from the power supply voltage supplied to the power supply line;
a capacitor connected to the input of the power supply circuit;
The control system is
The control system further comprising a startup circuit configured to sequentially supply the power supply voltage to the power supply circuits of the plurality of functional units with a time lag when the control system is powered on. A functional unit that implements a function for executing control processing for a controlled object and constitutes a control system,
a power supply line for applying a power supply voltage to the functional unit;
a power supply input terminal connected to a first end of the power supply line and receiving the power supply voltage;
a power output terminal connected to the second end of the power supply line and configured to be connectable to the power input terminal of a subsequent unit that forms the control system together with the functional unit;
a first power supply circuit that generates an internal power supply voltage from the power supply voltage supplied to the power supply line;
a capacitor connected to the input of the first power supply circuit;
an internal circuit that receives the internal power supply voltage and executes the function;
When the power supply voltage is input to the power input terminal, the power supply voltage is first supplied to the first power supply circuit of the functional unit, and the first power supply circuit of the subsequent unit is supplied with a time lag. and a start-up circuit configured to supply the power supply voltage to . The starting circuit is
a connection unit configured to switch whether or not to electrically connect the input of the first power supply circuit to the power supply line;
a control circuit that controls the connecting portion;
a second power supply circuit connected to the power supply line and supplying an operating voltage for operating the control circuit to the control circuit;
The functional unit is
After the connecting portion of the functional unit electrically connects the input of the first power supply circuit to the power supply line, the connecting portion is operated by the control circuit of the subsequent unit. an activation signal generation circuit for generating an activation signal for instructing activation timing;
3. The functional unit according to claim 2, further comprising a signal output terminal for outputting said activation signal from said activation signal generating circuit to said subsequent unit. the connection unit is a switch provided between the power supply line and an input of the first power supply circuit;
the first power supply circuit includes the activation signal generation circuit;
4. The functional unit according to claim 3, wherein said activation signal generation circuit generates said activation signal after an activation time elapses from when said switch is turned on. the functional unit and the succeeding unit have address values for addressing the functional unit and the succeeding unit relative to the foremost unit in the control system;
When the address value is given, the control circuit calculates a waiting time until activation of the connection unit, and activates the connection unit after the standby time has elapsed,
The control circuit includes the activation signal generation circuit, and the activation signal generation circuit generates the address value to be assigned to the subsequent unit based on the address value of the functional unit. 5. The functional unit according to claim 4, which generates a signal indicative of said address value as said activation signal. the input of the first power supply circuit is connected to the power supply line;
The starting circuit is
a switch provided between the input of the first power supply circuit and the power supply output terminal in the power supply line;
a control circuit for controlling the switch to turn on the switch in response to an activation signal;
a second power supply circuit connected to the power supply line and supplying an operating voltage for operating the control circuit to the control circuit;
The first power supply circuit,
3. The functional unit according to claim 2, further comprising an activation signal generation circuit for generating said activation signal when an activation time elapses from the start of supply of said power supply voltage to said first power supply circuit. an input voltage of the first power supply circuit is a voltage higher than the power supply voltage;
The connecting part is
6. The third power supply circuit according to claim 3, comprising a third power supply circuit activated by said activation signal to convert said power supply voltage into an input voltage of said first power supply circuit and charge said capacitor. functional unit. an input voltage of the first power supply circuit is a voltage higher than the power supply voltage;
The functional unit is
7. The functional unit according to claim 6, further comprising a third power supply circuit activated by said activation signal to convert said power supply voltage into an input voltage of said first power supply circuit and charge said capacitor.

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