JP5101660B2 - Programmable controller - Google Patents

Description

  The present invention relates to a programmable controller that sets an optimum pulse for driving and holding an output circuit regardless of the type of the output circuit.

  Conventionally, an output circuit that has been used in a programmable controller is roughly divided into a relay output circuit and a transistor output circuit. The external load connected to the programmable controller is driven by these two types of output circuits.

  FIG. 11 is a diagram illustrating an overall configuration of a conventional programmable controller. In addition, in each figure, the same code | symbol shows the same or equivalent part.

  In FIG. 11, a programmable controller main body 10A includes an input circuit 17 for inputting an electrical signal from a detection device A such as a sensor via each input terminal, an output circuit 18 for outputting the output signal via each output terminal, The microcomputer is mainly composed of a CPU, ROM, RAM and the like. The programmable controller body 10A controls an external load such as the driving device B through the output circuit 18 by a sequence program arbitrarily set by the user.

  In the programmable controller, it is a well-known fact that the user can arbitrarily expand the function, and there are a relay expansion I / O unit 20A and a transistor expansion I / O unit 30A which are units for expanding the number of input / output points. In addition, there are an analog I / O unit 40A that is an analog input / output compatible unit, a communication unit 50A that is a communication function expansion unit, and a special unit 60A that is a unit that expands other functions.

  An invention for suppressing power consumption and reducing heat generation of a relay output circuit used in a programmable controller is already known (see, for example, Patent Document 1). In this conventional example, a switching voltage is applied to a relay coil in a relay output circuit adapted for a programmable controller to drive a relay contact and then hold it. That is, a drive pulse with a long on-time is applied, and a holding pulse with a shorter on-time than the drive pulse is applied at a period of the predetermined time T for a predetermined time t2 after the predetermined time t1 has elapsed. FIG. 12 is a timing chart showing the relationship between the driving pulse and the holding pulse in the conventional example.

  Since the electric power for holding the relay contact is smaller than the electric power for driving the relay contact, when the relay contact is held in the ON state, a holding pulse is applied at a period of a predetermined time T. Thus, the relay contact can be held. Therefore, when the conventional method is used, the power consumption and the heat generation of the entire product can be reduced as compared with the case where the relay contact is held by continuously supplying a predetermined current.

JP-A-9-81212

  The conventional technique largely depends on the characteristics of the relay contact in the relay output circuit used in the conventional programmable controller. FIG. 13 is a side view showing the internal structure of the relay contact. In FIG. 13, when a current is passed through the relay coil 91 in the direction from the terminal X to the terminal Y, a magnetic field is generated from the winding attached to the iron core inside the relay coil 91 and the movable contact is moved to the fixed contact 93 by electromagnetic force. 94 is aspirated. When the fixed contact 93 and the movable contact 94 are attracted, the contact is turned on, and the terminals a and b are in a conductive state. When no current flows through the relay coil 91, the fixed contact 93 and the movable contact 94 do not come into contact with each other due to the stress of the spring 92, and the contact is turned off. Thus, driving and holding of the relay contact are affected by factors such as the number of turns of the relay coil 91, the material and shape of the iron core in the coil, and the stress of the spring 92. For this reason, the conventional method as described above is effective only at a specific relay contact.

  Further, when relay contacts with different characteristics are controlled with the same drive pulse, hold pulse, and on times t1 and t2 and on cycle T corresponding to each pulse, the output on state may not be held. Further, in contrast to the above, unnecessary drive pulses and holding pulses with a long on-time may be applied to the output circuit, and there is a possibility that power consumption cannot be reduced efficiently. Therefore, when only the relay contact is changed, it is necessary to change the pulse generation circuit in order to set the drive pulse ON time t1, the hold pulse ON time t2, and the hold pulse ON period T.

  Further, when the relay output circuit having a plurality of characteristics is controlled by a single CPU in the case of using an additional I / O unit or the like in order to expand the number of input / output points of the programmable controller, the above-described conventional method is used. May not be able to maintain the output-on state, and does not have a significant effect in reducing power consumption and heat generation. The technique of the conventional example is effective when a single type of relay contact and a relay contact having similar characteristics are used.

  FIG. 14 shows an output waveform of an output circuit (not shown) when the conventional technique is applied to the transistor output expansion I / O unit 30A and a holding pulse is applied.

  FIG. 14A shows drive pulses and holding pulses input to each output circuit, and the output waveform of the relay output circuit is turned on as shown in FIG. 14B by the input driving pulses and holding pulses. Although the output state is held, the output waveform of the transistor output circuit is the output state shown in FIG. As shown in FIG. 14, the transistor output circuit has a fast response speed unlike the relay output circuit, and thus causes an erroneous output in conjunction with the holding pulse.

  Further, in the case where the ON state of a plurality of relay contacts having the same characteristics in the relay output circuit is held, the relationship between the drive pulse and the hold pulse is shown in FIG. 15A, and further, the power consumption of the entire relay output circuit. Is shown in FIG. Since the power consumption of the entire relay output circuit has the characteristics shown in FIG. 15 (b), the fluctuation of the current when the holding pulse is output is large, so the relay output circuit of the programmable controller becomes a noise source and is connected to the programmable controller. There is also a problem of affecting the peripheral devices and devices sharing the same power source.

  The present invention has been made to solve the above-described problems, and obtains a programmable controller capable of setting an optimum pulse for driving and holding the output circuit regardless of the type of the output circuit. For the purpose.

  In addition, the present invention has been made to solve the above-described problems, and for maintaining the relay contact by not synchronizing the transmission timing of the holding pulse for the plurality of relay contacts for each relay contact. It is an object of the present invention to obtain a programmable controller that can suppress noise caused by pulse output.

The programmable controller which concerns on this invention is equipped with the programmable controller main body which drives the 1st external load, and the said programmable controller main body consists of the relay output circuit which outputs the signal which drives the said 1st external load. The circuit, the control means for outputting the output command, the characteristic information for specifying the output form of the first output circuit is read as an externally set voltage level signal, and read by the input unit Characteristic information corresponding to the voltage level signal is identified, an output form corresponding to the characteristic information is set, and a predetermined pulse is sent to the first output circuit according to the set output form based on the output command. look including a first output means having an output for outputting said first input-output means, the output mode, driving the output contacts And a holding pulse that is applied after a lapse of a predetermined time from the application of the driving pulse and holds the output contact in an ON state, and the ON time of the holding pulse is set to be longer than the ON time of the driving pulse. At least one of the on-time or on-period of the holding pulse is set to be shorter, and the correspondence relationship between the type information of the output contact, the on-time of the driving pulse, and the on-time and on-period of the holding pulse And the ON time of the drive pulse and the ON time and ON cycle of the holding pulse can be varied based on the type of the output contact .

  The programmable controller according to the present invention can set an optimum pulse for driving and holding the output circuit regardless of the type of the output circuit.

It is a figure which shows the structure of the programmable controller which concerns on Embodiment 1 of this invention. It is a flowchart which shows operation | movement of the programmable controller which concerns on Embodiment 1 of this invention. It is a flowchart which shows operation | movement of the programmable controller which concerns on Embodiment 1 of this invention. It is a figure for demonstrating the output form corresponding to the characteristic information of the output circuit of the programmable controller which concerns on Embodiment 1 of this invention. It is a timing chart which shows operation | movement of the input / output interface circuit of the programmable controller which concerns on Embodiment 2 of this invention. It is a timing chart which shows operation | movement of the input / output interface circuit of the programmable controller which concerns on Embodiment 2 of this invention. It is a timing chart which shows operation | movement of the input / output interface circuit of the programmable controller which concerns on Embodiment 2 of this invention. It is a timing chart which shows operation | movement of the input / output interface circuit of the programmable controller which concerns on Embodiment 2 of this invention. It is a flowchart which shows operation | movement of the programmable controller which concerns on Embodiment 2 of this invention. It is a flowchart which shows operation | movement of the programmable controller which concerns on Embodiment 2 of this invention. It is a figure which shows the whole structure of the conventional programmable controller. It is a timing chart which shows the relationship between the drive pulse and holding | maintenance pulse of a prior art example. It is a side view which shows the internal structure of a relay contact. It is a timing chart which shows operation | movement of the relay output circuit and transistor output circuit of a prior art example. It is a timing chart which shows the power consumption of the drive pulse and holding pulse which drive and hold | maintain several relay output circuits of a prior art example simultaneously, and the whole relay output circuit.

  Hereinafter, preferred embodiments of a programmable controller of the present invention will be described with reference to the drawings.

Embodiment 1 FIG.
A programmable controller according to Embodiment 1 of the present invention will be described with reference to FIGS. 1 is a diagram showing a configuration of a programmable controller according to Embodiment 1 of the present invention. In addition, in each figure, the same code | symbol shows the same or equivalent part.

  In FIG. 1, the programmable controller according to the first embodiment of the present invention includes a programmable controller body 10, a relay expansion I / O unit 20 as necessary, and a transistor expansion I / O unit 30 as necessary. It has been. The analog I / O unit, communication unit, special unit, etc. are omitted.

  The programmable controller body 10 includes a CPU (control means) 11, an input / output interface circuit (first input / output means) 12, an output circuit (relay output circuit) 13 connected to an external load O such as a driving device, An input / output interface circuit 14 and an output circuit (relay output circuit) 15 connected to an external load O such as a driving device are provided. The input / output interface circuit 12 includes a time measurement circuit 121, and the input / output interface circuit 14 includes a time measurement circuit 141. Further, the input circuit and the like are omitted.

  The extension I / O unit 20 is provided with an input / output interface circuit (second input / output means) 21 and an output circuit (relay output circuit) 22 connected to an external load O such as a drive device. The input / output interface circuit 21 includes a time measurement circuit 211. Further, the input circuit and the like are omitted.

  The extension I / O unit 30 includes an input / output interface circuit 31 and an output circuit (transistor output circuit) 32 connected to an external load O such as a driving device. Note that the input circuit and the like are omitted.

  Next, the operation of the programmable controller according to the first embodiment will be described with reference to the drawings.

  2 and 3 are flowcharts showing the operation of the programmable controller according to Embodiment 1 of the present invention. FIG. 4 is a diagram for explaining an output form corresponding to the characteristic information of the output circuit of the programmable controller according to the first embodiment of the present invention.

  First, in step 100, when a power supply voltage is applied to the power supply of the programmable controller, each input / output interface circuit 12, 14, 21, 31 receives characteristic information of each output circuit 13, 15, 22, 32 connected thereto. Read and set the output form of each output circuit.

  4A to 4D show characteristic information circuits for identifying characteristic information. FIG. 4E shows the output form corresponding to the characteristic information of the output circuit. This output form is an output waveform of the input / output interface circuit and an input waveform of the output circuit. The characteristic information circuit shown on the right side of FIGS. 4A to 4D enables switching of characteristic information by two external jumper resistors 80 connected to the MOD1 pin and the MOD2 pin of the input / output interface circuit. The input / output interface circuit uses a combination of two jumper resistors 80 to change the output circuit characteristic information to “relay A”, “relay B”, “relay C” or “other than relay” and output contact (relay contact). Different types can be distinguished and characteristic information can be entered. The input / output interface circuit stores the correspondence between the types of output contacts (relay contacts) and the types of output forms as shown in FIG.

  For example, when the input / output interface circuit 12 reads “H (high)” and “H (high)” from the characteristic information circuit of FIG. 4A through the MOD1 pin and the MOD2 pin, FIG. ), As the characteristic information of the output circuit 13, the output circuit 13 is recognized as a relay output circuit in distinction from “relay A”. Further, the input / output interface circuit 12 sets the output form of the first stage in FIG. 4E as the output form from the correspondence between the type of output contact (relay contact) and the type of output form.

  Similarly, for example, when the same input / output interface circuit 12 reads “L (low)” and “H (high)” from the characteristic information circuit of FIG. 4B through the MOD1 pin and the MOD2 pin, As shown in FIG. 4E, as the characteristic information of the output circuit 13, the output circuit 13 is recognized as a relay output circuit as distinguished from “relay B”. Further, the input / output interface circuit 12 sets the output form of the second stage in FIG. 4E as the output form from the correspondence between the type of output contact (relay contact) and the type of output form.

  Each input / output interface circuit 12, 14, 21, 31 recognizes the characteristic information of the connected output circuits 13, 15, 22, 32, and then connects the output based on the correspondence between the characteristic information and the output form. When the circuit is a relay output circuit (relay A, relay B, relay C), the state transits to the standby state of the next step 110, and when the connected output circuit is other than the relay output circuit (other than the relay), Transition is made to the standby state of step 140 in FIG.

  At this time, the output circuits 13 and 15 built in the programmable controller main body 10 are assumed to be relay output circuits, and the relay contact (output contact) of the relay output circuit of the programmable controller main body 10 and the output circuit 22 in the extension I / O unit 20 are used. It is assumed that the relay contacts (output contacts) have different characteristics.

  Next, in step 110, the CPU 11 in the programmable controller body 10 responds to a sequence program arbitrarily set by the user based on a signal from a detection device such as a sensor connected to an input circuit (not shown). As a result of the execution, an output command is transmitted to each of the input / output interface circuits 12, 14, and 21.

  Each input / output interface circuit 12, 14, 21 receives this output command, and compares the designated address of the output command with the address owned by each input / output interface circuit. At this time, it is assumed that any of the input / output interface circuits 12, 14, and 21 has an address that matches the designated address of the output command, and the output command is a command to turn on the output circuit. The input / output interface circuit that owns an address that does not match the destination address specified in the output command shifts to a standby state.

  Next, in step 120, the input / output interface circuits 12, 14, and 21 having addresses that match the designated address of the output command recognize that the output command is a command to turn on the output circuit, and then set the output format set. Based on the above, a drive pulse having a long ON time t1 for driving the relay contact is transmitted to any one of the output circuits 13, 15, and 22, and the relay contact in the relay output circuit starts an ON operation.

  After the relay output circuit connected to the input / output interface circuit starts the on operation and the time measuring circuits 121, 141, 211 in the input / output interface circuits 12, 14, 21 recognize that a predetermined time (on time t1) has elapsed. The input / output interface circuit stops transmitting the drive pulse. At this time, when a new output command is transmitted to the input / output interface circuit that is outputting the drive pulse before the elapse of the predetermined time, the information on the output command is confirmed again. The relay contact in the relay output circuit when the input / output interface circuit stops transmitting the drive pulse after recognizing the elapse of the predetermined time is turned on because the current flows for a predetermined time, and the external load is driven. The input / output interface circuit stops the transmission of the driving pulse, and at the same time, resets the time measurement and proceeds to the next step 130.

  Next, in step 130, each input / output interface circuit uses the time measurement circuits 121, 141, and 211 based on the set output form, and the relay output circuits when the relay contacts are kept on. A holding pulse having a short on-time t2 is transmitted for each of 13, 15, and 22 every on-period T. Thus, the ON state of the external load is maintained by maintaining the ON state of the relay contact. If a new output command is transmitted to the input / output interface circuit that is outputting the hold pulse before the time measurement circuit recognizes the elapse of the predetermined time, the output command information is confirmed again.

  The drive pulses and holding pulses output from the input / output interface circuit 21 of the extension I / O unit 20 are different from the driving pulses and holding pulses output from the input / output interface circuits 12 and 14 in the programmable controller main body 10. The drive pulses and holding pulses transmitted by the input / output interface circuits 12, 14, and 21 are pulses that are optimal for the characteristics of the connected output circuit.

  The input / output interface circuit 31 in the extension I / O unit 30 outputs the output circuit 32 based on the correspondence relationship between the characteristic information and the output form after the output circuit 32 to be connected is distinguished from other than the relay output circuit in step 100. The form is set, and the process proceeds to step 140 in FIG. It is assumed that the input / output interface circuit 31 has an address that matches the designated address of the output command, and the output command is a command to turn on the output circuit.

  In step 140, after the input / output interface circuit 31 recognizes that the output command is a command to turn on the output circuit, the input / output interface circuits 12, 14, 21 connected to the relay output circuit based on the set output form. Unlike the above, only the drive pulse is transmitted to the transistor output circuit 32 to drive the external load.

  As described above, according to the first embodiment, regardless of the type of output circuit, the input / output interface circuit connected to each output circuit can identify the characteristic information and output form relating to the output circuit. Based on the output form and the time measurement circuit, it is possible to set an optimum pulse for driving and holding the connected output circuit.

Embodiment 2. FIG.
A programmable controller according to Embodiment 2 of the present invention will be described with reference to FIGS. The configuration of the programmable controller according to the second embodiment of the present invention is basically the same as that of FIG. 1 of the first embodiment. However, each input / output interface circuit includes two time measurement circuits, that is, a time measurement circuit 1 and a time measurement circuit 2. In FIG. 1, each output circuit is a relay output circuit or a transistor output circuit having eight output contacts (relay contacts).

  The operation of the programmable controller according to the second embodiment will be described with reference to the drawings.

  5, 6, 7 and 8 are timing charts showing the operation of the input / output interface circuit of the programmable controller according to the second embodiment of the present invention. 9 and 10 are flowcharts showing the operation of the input / output interface circuit of the programmable controller according to the second embodiment of the present invention.

  5 (a), 6 (a), 7 (a), and 8 (a) show that one input / output interface circuit having a plurality of relay contacts is simultaneously connected to a plurality of relays in response to an output command from the CPU. The driving pulse and holding pulse at the time of driving and holding the contact are shown, and the respective figures (b) are diagrams showing the power consumption required for the entire relay output circuit. The characteristics of the relays shown in FIGS. 5, 6 and 7 are the same, and only the characteristics of the relay shown in FIG. 8 are different.

  The holding pulse is transmitted at a timing calculated based on the input / output interface circuit connected to each output circuit and the time measuring circuit, and the transmission timing of the holding pulse to each relay contact connected to one input / output interface circuit is mutually It is not synchronized.

  As shown in FIGS. 5, 6, 7, and 8 (a), the timing of the holding pulse transmitted to each relay contact by the input / output interface circuit is not synchronized for each relay contact, so that one input / output interface circuit is provided. The power consumption of the entire relay output circuit connected to the circuit is as shown in FIG. 5, FIG. 6, FIG. 7 and FIG. 8B, and the peak value of the power consumption related to the holding pulse is suppressed. 5A and 5B are characteristics when two relay contacts are simultaneously turned on, and FIGS. 6A and 6B are characteristics when four relay contacts are simultaneously turned on. FIGS. 7A and 7B show characteristics when seven relay contacts are simultaneously turned on. Further, FIGS. 8A and 8B show characteristics when three relay contacts having different characteristics from those shown in FIGS. 5, 6, and 7 are simultaneously turned on.

  Further, since the power consumption is smoothed as the peak value of the power consumption related to the holding pulse is suppressed, it is possible to reduce noise generated by the output circuit of the programmable controller.

  The timing at which the input / output interface circuit transmits a holding pulse to each connected relay contact depends on the number of relay contacts that hold the relay contact ON and the characteristics of the relay contacts. The holding pulse transmission timing delay time D is T for the voltage application period (ON period) of the relay contact required to hold the ON state, t2 for the voltage application time required to hold the ON state of the relay contact, Assuming that the number of relay contacts that keep the ON state is N (N> 1), D = (T−t2) / (N−1). From this relational expression, the input / output interface circuit calculates the transmission timing delay time D of the holding pulse. FIG. 5, FIG. 6, FIG. 7 and FIG. 8A show the voltage application time t1 of the drive pulse, the voltage application period T, the voltage application time t2, and the transmission timing delay time D of the holding pulse. This transmission timing delay time D is, for example, the time from the start of transmission of the current (lower) hold pulse to the start of transmission of the next (upper) hold pulse in FIG.

  First, in step 200, when a power supply voltage is applied to the power supply of the programmable controller, each input / output interface circuit 12, 14, 21, 31 receives characteristic information of each output circuit 13, 15, 22, 32 connected thereto. Read and set the output form of each output circuit. Then, transition is made to the output standby state in the next step 210.

  Next, in step 210, when the input / output interface circuit receives an output command from the CPU 11 of the programmable controller body 10, the process proceeds to step 220. If the output command is not received, the input / output interface circuit returns to the output standby state. Transition.

  Next, in step 220, the number N of relay output circuits to be turned on and relay output circuits to be turned on in the output command is confirmed, and a drive pulse is transmitted to the relay output circuits to be turned on. Then, the process proceeds to step 230. At this time, when the number N of relay output circuits to be turned on is 0, the state transits to the output standby state in step 210.

  Next, at step 230, at the same time as transmitting the drive pulse, the time measuring circuit 1 in the input / output interface circuit starts measuring the transmission time of the drive pulse. This time measurement circuit 1 continues the time measurement until the ON time t1 of the set output form elapses. When the input / output interface circuit receives a new output command (different from the previously received content) during the time measurement, the process proceeds to step 220. After confirming the elapse of the ON time t1 of the set output form, the input / output interface circuit transitions to steps 240 and 260 depending on the number N of relay output circuits to be turned on. At this time, the relay contact in the relay output circuit is turned on since a current flows for a predetermined time.

  If the number N of relay output circuits to be turned on is 1, the transmission of drive pulses is stopped in step 240 and the measurement time of the time measurement circuit 1 is reset. Thereafter, based on the set output form, the input / output interface circuit transmits a holding pulse to the relay contact holding the ON state. The input / output interface circuit stores the correspondence between the type of output contact (relay contact) and the type of output form.

  Next, in step 250, the elapsed time of voltage application t2 necessary for maintaining the relay contact ON state is measured by the time measuring circuit 1, and the input / output interface circuit recognizes the elapsed time t2 and holds it. Stop pulse transmission. Next, the input / output interface circuit measures the passage of the voltage application period (on period) T of the relay contact required to maintain the on state by the time measuring circuit 1 and recognizes the passage of the predetermined time T. The measurement time of the time measurement circuit 1 is reset. Even during this process, when the input / output interface circuit receives a new output command, the contents of the output command are confirmed again. When there is no change in the contents of the output command, a holding pulse is transmitted to the relay contact that holds the ON state again.

  If the number N of relay output circuits to be turned on is larger than 1, in step 260, the input / output interface circuit determines the number N of relay output circuits to be turned on and the holding pulse ON cycle T based on the set output form. The hold pulse transmission timing delay time D is calculated from the voltage application time t2 required to hold the relay contact ON state. The input / output interface circuit stores the correspondence between the type of output contact (relay contact) and the type of output form, and the correspondence between the number N of relay contacts to be turned on and the holding pulse transmission timing delay time D. I remember it. After calculating the hold pulse transmission timing delay time D, transmission of the drive pulse is stopped and the measurement time of the time measurement circuit 1 is reset. After the measurement time of the time measurement circuit 1 is reset, the holding pulse is transmitted to the relay contact that holds the first ON state in order from the youngest number of output points.

  In step 270, the input / output interface circuit measures the elapse of the holding pulse transmission timing delay time D by the time measurement circuit 1, and the voltage application time required for holding the relay contact ON state in the time measurement circuit 2. Measure the course of t2. When the operation of the input / output interface circuit differs depending on the relationship between the transmission delay time D and the voltage application time t2, and when the relationship of D> t2 (FIG. 5) is established, the time measurement circuit 2 uses the hold pulse. Before confirming the elapse of the transmission timing delay time D, the elapse of the voltage application time t2 is confirmed, and the process proceeds to step 280.

  Further, when the relationship of D <t2 (FIGS. 7 and 8) is established, the time measurement circuit 1 determines that the hold pulse transmission timing delay time D before the time measurement circuit 2 confirms that the voltage application time t2 has elapsed. , The holding pulse is transmitted to the relay contact that holds the next ON state, and the measuring time of the time measuring circuit 1 is reset. Thereafter, the time measurement circuit 1 starts time measurement again. After comparing the number of holding pulse transmissions with the number N of relay contacts to be turned on, if the number of holding pulse transmissions is less than the number N, the time measurement circuits 1 and 2 again hold the holding pulse transmission timing D and the voltage application time. Measure the course of t2. This is repeated, and in the case of FIG. 7, after the time measurement circuit 2 confirms the elapse of t2, the process proceeds to step 280. In the case of FIG. 8, the number of holding pulse transmissions becomes equal to N before the elapse of t2. Therefore, the time measurement circuit 2 confirms the elapse of t2 and proceeds to step 290.

  Further, in the case of D = t2 (FIG. 6), since the time measurement circuit 1 confirms the passage of D and the time measurement circuit 2 confirms the passage of t2, the process proceeds to step 280 or 290 as described above. Will be.

  After the time measurement circuit 2 confirms that the predetermined time t2 has elapsed, in step 280, the transmission of the holding pulse to the relay contact holding the first ON state is stopped, and the measurement time of the time measurement circuit 2 is reset. . Thereafter, the time measurement circuit 2 starts time measurement again. When the time measurement circuit 1 confirms that the predetermined time D has elapsed, the time measurement circuit 1 transmits a holding pulse to the relay contact that holds the next ON state. To do. The time measurement circuit 1 resets the measurement time, starts time measurement again, and proceeds to step 290.

  In step 290, when the time measurement circuit 2 confirms that the predetermined time D has elapsed, the holding pulse transmission is stopped and the measurement time of the time measurement circuit 2 is reset. Thereafter, the time measurement circuit 2 starts time measurement again. After the time measurement circuit 2 starts time measurement, the number of holding pulse transmissions stopped is compared with the number N of relay contacts to be turned on. If the number N is equal to the number of holding pulse transmissions stopped, the process proceeds to step 300.

  Also, the number of holding pulse transmission stops is compared with the number N of relay contacts that are turned on. If the number of holding pulse transmission stops is not equal to the number N, then the number N is compared with the number of holding pulse transmissions. If the comparison results are equal, the time measurement circuit 2 measures and confirms the passage of the predetermined time D again. If the comparison results are different, the process proceeds to step 280.

  When the input / output interface circuit receives a new output command while the time measurement circuits 1 and 2 are measuring the passage of time, the contents of the output command are checked again. When there is no change in the content of the output command, the time measurement circuits 1 and 2 continue the time measurement, but when there is a change in the content of the output command, the process proceeds to step 220.

  As described above, according to the second embodiment, the input / output interface circuit sets the output form by identifying the characteristic information based on the characteristic information of the output circuit and the output form corresponding to the characteristic information, and measures the time. Based on the measurement time by the circuits 1 and 2, a driving pulse is transmitted to each relay contact, and then a holding pulse is transmitted to each relay contact at a timing that is not synchronized with each other. Thereby, the peak value of the power consumption regarding the holding | maintenance pulse which the relay output circuit which has a some relay contact connected to one input / output interface circuit requires can be reduced. Accordingly, power consumption is smoothed, and noise generated by the output circuit of the programmable controller can be reduced.

  In each of the embodiments described above, the output form information related to the output circuit is stored in the input / output interface circuit. However, the output form information may be stored in a storage medium or an external circuit.

  In addition, the time measurement circuit for calculating the transmission timing of the holding pulse may be provided separately from the input / output interface circuit without being built in the input / output interface circuit.

  Furthermore, a microcomputer and an external circuit can be used as a substitute for the input / output interface circuit and the built-in time measuring circuit.

  10 Programmable Controller Body, 11 CPU, 12 Input / Output Interface Circuit, 13 Output Circuit, 14 Input / Output Interface Circuit, 15 Output Circuit, 20 Additional I / O Unit, 21 Input / Output Interface Circuit, 22 Output Circuit, 30 Additional I / O Unit, 31 input / output interface circuit, 32 output circuit, 80 jumper resistance, 121 time measurement circuit, 141 time measurement circuit, 211 time measurement circuit.

Claims (3)

A programmable controller body for driving the first external load;
The programmable controller body is:
A first output circuit comprising a relay output circuit for outputting a signal for driving the first external load;
Control means for outputting an output command;
Identifying characteristic information for specifying the output form of the first output circuit as an externally set voltage level signal, and characteristic information corresponding to the voltage level signal read by the input part A first input / output unit having an output unit that sets an output form corresponding to the characteristic information and outputs a predetermined pulse to the first output circuit in accordance with the set output form based on the output command. viewing including the door,
The first input / output means includes
The output form is set to output with a drive pulse that drives the output contact and a holding pulse that is applied after a lapse of a predetermined time from the application of the drive pulse and holds the output contact in an ON state,
Setting at least one of the on-time or on-period of the holding pulse so that the on-time of the holding pulse is shorter than the on-time of the drive pulse;
Stores the correspondence between the type information of the output contact, the on-time of the drive pulse, and the on-time and on-cycle of the holding pulse,
A programmable controller , wherein an ON time of the drive pulse and an ON time and an ON cycle of the holding pulse can be varied based on the type of the output contact . An additional I / O unit for driving the second external load;
The additional I / O unit is
A second output circuit comprising a relay output circuit for outputting a signal for driving the second external load;
The characteristic information of the second output circuit is identified, an output form corresponding to the characteristic information is set, and a predetermined pulse is sent to the second output circuit according to the set output form based on the output command. The programmable controller according to claim 1, further comprising: second input / output means for outputting. The relay output circuit has a plurality of output contacts,
The first or second input means, a programmable controller of claim 1 or 2, wherein the on-time of the sustain pulses to be applied to the plurality of output contacts are set not synchronized with each other.

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