JPS6369333A - Sequence control system using power line carrier - Google Patents

Abstract

PURPOSE:To decrease a communication time by allowing a master station to decide the order of sequential transmission to a slave station making a reply and to inform a different wait time data to each slave station in response to the order thereby having only to need one confirming time till the stabilized data after transmission/reception changeover. CONSTITUTION:A data is outputted simultaneously from the master station 3 to all the slave stations 51-5n and data communication is acknowledged by adding a check bit at the transmission from the slave stations 51-5n. The communication of an input data from the slave stations 51-5n is confirmed by adding a check bit to the data sent simultaneously to all the slave stations 51-5n from the master station 3, resulting that the communication is attained by one transmission/reception by each station. Moreover, as a minimum unit of the number of input/output points to each station, the slave stations 51-5n are provided with the minimum unit of the number of communication stations then the number of input/output points is selected as the constitution. The communication with a communication establishing station is attained at a minimum required time by information the number of communication stations for the slave stations 51-5n to the master station at the point of time when the communication is established.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a sequence control system that performs sequence control using power supply wiring.

[Technical background of the invention and its problems] Generally, sequence control methods have been developed that perform sequence control using power supply wiring. However, sequence control using force transfer has the following problems, and has not been widely used for process control.

(1) In the case of a half-duplex system in which communication is performed by switching transmission and reception, if there is a slave station, it is necessary to switch transmission and reception for each station to check for transmission errors. For this reason,
When switching to transmission and reception, it takes time for the data to stabilize, which increases the time required for communication. (For example, l scan time/number of control points is several seconds, 732 points) (2) In order to shorten the communication time in (1), if transmitting and receiving are performed using different carrier frequencies, the equipment becomes complicated.
The disadvantage is that the price is high.

(3) The number of input/output points connected to the slave station is fixed.In order to receive and input the human output signal with the input/output unit of the sequencer, input/output units were required for both the master station and the sequencer.

(5) A conventional sequence controller consists of a sequencer and a control panel. In such a configuration, the input/output wiring between the sensor and load of the controlled device and the control panel is long. For this reason, when there is a change in the controlled equipment, the control panel and input/output wiring must be changed, resulting in a lack of flexibility.

[Purpose of the Invention] The purpose of the invention is to provide a sequence control system using a power carrier path that can control a controlled device online and communicate in the minimum necessary time depending on the number of input/output points of the controlled device. The goal is to provide the following.

Another object of the present invention is to enable the user to freely select the number of input/output points of the controlled device connected to the slave station depending on the location of use, and to switch the power supply with one touch without changing the communication format. An object of the present invention is to provide a sequence control system using a conveyance path.

Another object of the present invention is to shorten input/output wiring by creating a structure in which a master station and a sequencer can be directly connected without going through each other's input/output units, and slave stations can be installed near controlled equipment. An object of the present invention is to provide a sequence control system using a power carrier path, which aims to reduce the total cost of the sequence control system by standardizing slave stations.

[Summary of the Invention] According to this invention, data is output from a master station to all slave stations at once. Data communication confirmation is performed by adding check pits when transmitted from a slave station. Communication confirmation of input data from a slave station is performed by adding check pits to data sent from the master station to all slave stations at once. As a result, each station can communicate with one transmission and one reception.

Also, the minimum unit of input/output points for the station (in this example, 4 input points,
By having the minimum unit number of communication stations as a slave station (4 output points), the number of input/output points can be selected. By notifying the master station of the number of communication stations in the slave station at the time of establishing communication, it is possible to communicate with the station with which communication is established in the minimum required time. Furthermore, the input/output specifications from the master station to the sequencer were adapted to the pit path of the connected sequencer. As a result, the master station can be directly connected to the sequencer. As a result, it is possible to connect to any sequencer by simply changing the encoder/decoder that matches the pit path of the sequencer.

The slave station can control three-phase and single-phase loads and on-site sensors that have a wiring protection function, and can be installed near the controlled device to shorten input/output wiring and power wiring. By standardizing the father and son stations according to the motor capacity, we achieved cost reductions.

[Embodiment of the Invention] An embodiment of a sequence control system using a power transfer path of the present invention will be described below with reference to the drawings.

In FIG. 1, a power supply wiring (for example, an AC 100V line) JK is connected to a master station 3 and a plurality of slave stations 51.

5! ,...5n are connected. Each of the slave stations 51
s52,...5n are single-phase controlled devices '1#'
1173, three-phase controlled equipment 24, and sensor 91
92 is connected. Furthermore, a sequencer 1 is connected to the master station 3 for controlling the controlled devices 71e72s'' and 7n using inputs from sensors. Status information is sent to the slave station 51.

5: , . . . 5n, the AC power supply wiring 1#H takes in the information via the station 3, and sends the control information to the master station 3. Controlled equipment 7 via AC power supply wiring 1° and slave stations 51*52+...5n
1. 7. , -7nK is supplied.

FIG. 2A is a detailed block diagram of the master station 3, in which the sequencer connection terminals 13. Encoder 15. Decoder 17. Serial Root-Arel Converter 19. No arm serial converter 21. l chip CPUJJ,.

and deer transportation units),? I have 51i. lchiy
7' CPU 231 has input ports 27B, 27
．． .

Output yj? -29g, 29. , Random Access Memory (RAM) J 1 , Read Only Memory (ROM) 33 , ALU and Aki, Muleta 3
5. and a control circuit 37. The power transfer unit 251 superimposes control information from the sequencer 11 on the power supply wiring. That is, the power transfer unit 251 has 5
Approximately 5 degrees of FSKil is applied to the high frequency current from 0 kHz to 300 kHz, and the maximum speed is 4800 bps.
This is a transceiver IC that enables the transmission and reception of serial data up to As such a transceiver IC,
For example, in the US, Nal Semiconductor model LM1
A G.893 carrier current transceiver can be applied. Furthermore, a message device 26 consisting of a 7-segment LED is connected to the output port 293 of the CPU 231. Note that the master station has an encoder and a decoder that can be directly connected to the sequencer.

As a result, information on the controlled device can be directly taken into the sequencer without using the input/output unit of the sequencer. By changing the encoder and decoder according to the sequencer to be connected, it is possible to connect to any sequencer.

The master station is divided into an input port (input port) and an output port (output port) as shown in FIG. 2A. The external shape of the crab knit is shown in Figure 2B. The input unit 400 is configured so that the input status transmitted from the child station can be determined by the LED 40j indicating the input status of 64 points and the number 401 indicating the input address. Also 402
A blinking RUN display indicating that the CPU is operating and an "H" display indicating the HIGH side switching direction of the display changeover switch 403 are also added to the LED.The display changeover switch 403 has 64 input points. Of these, the bottom 32 points and the top 3
This is a changeover switch for switching and displaying two operating states. The alarm display 26 displays the address of the slave station with which communication is no longer performed normally.

A reset button 405 is a companion button that executes the master station program from its initial state. The tie 06 is a connector for connecting the wiring between the incoming knit and the outgoing knit. The scroll table 4θ7 is an electric current for superimposing power transfer data.
Used to connect.

A front view of the dekani knit is shown in FIG. 2C. The external shape of the kani knit is similar to that of the kani knit that comes in. Out crab knit 41
0 indicates that the input status from the sequencer is being output to the slave station d' IJD 412 and a number 411 indicating the output address of the sequencer are provided. 6 display changeover switch 413 is the lower 32 points of the output points 64. Switch the display of the top 32 points.

A connector 414 is provided below the display changeover switch 413 for connection to the input crab unit.

FIG. 3A is a detailed block diagram of the slave station. Slave station 51*5
2m...5n are the CPU chip 232°, the power transfer unit 25, and the photothyristor 39m, respectively.
, 39. ．． 39s, 394.

7 each thyristor 391. 39g, 393
.

394 performs conversion from TTL level to AC100V level. (This example shows the case where the number of input and output points of the slave station is 4 points each.) One slave station unit has 4 points each of input and output points (maximum 3 points each of input and output points).
2 points) can handle data.

This can be regarded as a state in which a plurality of communication stations are operating within one slave station. As a result, there is no difference in the format of the data to be handled whether one unit handles data for a plurality of rounds or data for - rounds. In other words, there is no effect on the parent station at all. The number of stations handled by one slave station unit is 1 station (4 input/output points each), 2 stations (8 input/output points each), 4 stations (16 input/output points each), 8 stations (32 points each) using DIP switches. input/output).

By adopting such a configuration, it is possible to have flexibility in the number of input/output points that can be handled by the slave station. The outer shape of the slave station is
Shown in Figure B. The slave station 5 has a interrupter 50 for three-phase load protection.
1 and a circuit protector 502 for single-phase load protection.

A controlled power supply display 503 is an indicator that indicates that power is supplied to the power transfer path. A reset button 504 is a button that starts the CPU from an initial state.

Display sections 505 and 506 indicate sensor input status, and R
The UN display section 507 blinks when the CPU is operating. Display sections 508 to 511 indicate the output status, and error display section 513 lights up when communication with the master station is abnormal. The disconnection display section 514 lights up when communication with the master station is disconnected. Fuse 515 is a protection fuse for an external machine used in connector 516.

4A to 40 show the master station 3 and the slave stations 53, 5. .

...indicates the format of data exchanged with 5n. FIG. 4A shows common data blocks exchanged between a master station and a slave station. This common data block consists of a start bit (1 bit), transmitted/received data (16 bits), and a stop bit (1 bit). Transmission/reception data (16 bits) further includes command (4 bits), address (4 bits), data (input/output, other 4 bits), and CRC (Cye 11
c RadundancyCheck) code (4
bit).

FIG. 4B shows the data format when the master station transmits. This format initially has a high level VC1 pit and 4 low level dummy bits. This dummy bit is used to time the next 1 bit of power carrier unit receive data stabilization time and the high level start bit.The dummy bit is followed by 16 text bits, followed by 16 text bits. A low level stop bit follows. A plurality of pieces of data having such a bit configuration continue, and the stop bit of the final data has a 2-bit configuration. On the slave station side, when two stop bits continue, it is determined that data communication from the master station is complete. That is, the master station sends data to the slave stations all at once.

Figure 4C shows the data format used for slave station communication. The first 5 dummy bits are similar to the data format of the master station. This is followed by a 1 high level start bit, 16 text bits, and a 1 low level stop bit. In addition,
As shown in the figure, a dummy bit of 10 bits tc is provided between the data from the next slave station to adjust the timing. ≠J2niwo→ of the data to be processed is as follows, ・(: r:'::ri.

The operation of an embodiment of the present invention will be described below with reference to FIGS. 5A to 5G.

FIG. 5A is a flowchart of the control program on the master station side. First, in step f41, the input/output state, input/output device, and variables are initialized. Furthermore, a watchdog timer is set to prevent runaway. Thereafter, the watchdog timer is set at an appropriate point in the routine.Next, in step 43, a reset signal is sent to all the slave stations, the slave stations are put into the initial state, and the Stella F45 performs communication establishment processing. It processes the stations, checks the communication stations, determines the waiting time of the slave stations, and instructs the start station to transmit 2. Next, in step 42: A master meter (HL9) representing the order of the communicating slave stations is set to 1@o-. Further, in step 49, the alarm is reset. Next, in step 51, the address of the slave station that performs the HLQ communication is set, and the waiting time flag is reset in the Stella f53. Next, in step 55,
It is determined whether there is reception from the start station (station n). If there is no reception from n stations, the process advances to step 63. On the other hand, if there is reception from n stations, the process advances to step 51. Note that the determination in step 55 also includes determination of the stop bit for receiving communication from the slave station. In step 52, it is determined whether the frame is over. That is, if there is data even after the stop bit, it is an error and the process proceeds to Stella f63 to perform error processing. If it is determined in step f57 that there is no frame over, the CRC (Cy
If it is determined that there is an error as a result of the CRC check (clicR@dundancy Check), the process proceeds to step 63 and error processing is performed. On the other hand, if it is determined that the address is correct as a result of the CRC check, an address check is performed in step 61. That is, n(H
The address of the LQth slave station that communicates) is compared with the address in the communication data. If the result of the address check is an error, the Stella f63 processes the error and displays an alarm. On the other hand, the address check If the result is correct, data from the slave station is received in step 65. Next, in step 67, the ranking of the communicating slave stations is incremented. In Stella 7a69, it is determined whether the incremented rank of the slave station is less than or equal to the number of communication stations. If it is less than the number of communication stations, the process returns to step 51 and steps 51 to 69 are repeatedly executed.

On the other hand, if the number of communication stations has been exceeded, the process proceeds to step 71, and similarly to step 47, the nono parameter HL9 representing the order of the communicating slave stations is set to O.

Next, in step 73, the address of the HLQ-th slave station with which communication is to be performed is set, and in step 75, n is set in the address data parameter ADRD. Next, in step 77, it is determined from the Tn flag (see FIG. 7) whether station n is disconnected from the online system.

If it is disconnected, proceed to step 83VC.

On the other hand, if it is determined in step 77 that it is time to disconnect, it is determined in step 79 whether or not the wait time flag for station n is set. If the flag is set, the process advances to Stella f83 and the waiting time for station n is set.

If not set, in step 81 n
Set station data. In other words, CO shown in the 4th person diagram
MD and DATD are set. Furthermore, in step 85, COMD shown in the fourth person diagram.

Generate CRCD from ADRD and DATD. Next, in step &7, /? HL9 to Rameta X
A value doubled is set so that it can be used in the TRXDT set routine in step 89. That is, TRXD
Since the T data is one word, the byte address is doubled. In step 89, the COMD shown in the fourth person diagram is
, ADRD, DATD and C'RCD are set in a TRXDT buffer (not shown). Step 911
HL9 is incremented in the IC, and in step 93 it is determined whether HL9 is less than or equal to the number of communication stations. If it is less than or equal to 0 communication stations, the process returns to step 73, and steps 73 to 93 are repeatedly executed. . On the other hand,
If the number of communication stations is greater than or equal to the number of communication stations, in step 95 TR)G
) T to the slave station, and in step 97, the RUN lamp is blinked. As a result.

The data transmission to the slave station is completed, and the process returns to step 47 to repeat the same process. As shown in the flow of the main station main routine, when power transfer is frequently transmitted and received, it takes time for the data to stabilize, so the master station puts all the slave stations in the receiving state and sends them all at once. The data is then transmitted using the FNA mat shown in FIG. 4C. When this is completed, the data is transmitted to the master station in order from the start station of the slave station determined by communication establishment to the master station in accordance with the communication order in the 7 format shown in FIG. 4B. That is, data transmission can be performed by just one transmission/reception between the master station and all slave stations. Therefore, the stabilization time required for switching between transmission and reception is only required once, so the overall communication time is minimized. In this case, since it is necessary to perform a communication error check, the configuration is such that the error check can be performed with one transmission/reception. (This will be described later with reference to FIGS. 5E and 5F.) Next, a subroutine for establishing communication at the master station will be described with reference to FIGS. 5C and 5D. Establishing communication is a process of identifying the communication station from the address data communicated by the slave station and notifying the slave station of the transmission time from the start station.

First, in Stella 71199, the slave station address n is set to 0. Furthermore, the error counter HLO is initialized to 0 in Stella 71'101. next,
In step 103, data is requested from the n station, that is, an n station reception command is transmitted. Next, when Stella'fxos receives data from station n, Stellar f107 performs an error check on the received data. As a result of the error check, if there is an error, the error counter is incremented in step 111, and the process proceeds to step 11.
If it is determined in step 3 that the value of the error counter is 2, that is, if it is determined that an error has occurred twice, an alarm for the n station is outputted in step 115. That is, n
The station will be displayed on the alarm in Figure 2A. As a result, since there is no station with which this station communicates, no communication will be made to this station from now on.

On the other hand, if it is determined in step i i , tic that the value of the error counter is not @2', the process returns to step 103 . On the other hand, when Stella f107 h determines that the received data is correct, in step 109 the flag Qn of the slave station to be communicated is set, and in step 117
Proceed to. In step 117, the value of station n is incremented, and in step 119, it is determined whether n is "16#", that is, whether initialization has been completed for all slave stations (in this embodiment, there are slave stations O to 15). .If initialization is not completed, return to step 1ozlfc and perform steps 101 to 119.
is executed repeatedly. On the other hand, when initialization is completed for all slave stations, the transmission items of the slave stations are determined in step 121. At this time, slave stations that are not communicating are disconnected. Next, the process proceeds to step 123, where the order of the communicating slave stations is initialized to O, and at step 1251C, the address of the slave station that performs all communications is set to 1 (the address of the slave station that performs all communications is set at L9th), and the error counter is set at step 127.
Initialize ILO to 0.

Next, in step 129, the n-station waiting time data is transmitted to the n-station, and the n-station waiting time data repeatedly sent back from n4 is received in Stella 7#JJJ.

Next, in step 133, it is determined whether the received data is in error. If it is determined that there is an error in step 133, the error counter is incremented in step 135, and the error counter is incremented in step 137.
If it is determined that there has been an error, the Stella f139 displays the n station in error on the alarm 26 in FIG. 2A. On the other hand, if it is determined in step 137 that the error has not occurred twice, the process returns to Stella 7 #129.

On the other hand, if it is determined in step 133 that the received data is correct, the process proceeds to step 141, where the rank of the communicating slave station is incremented, and in step 143, it is determined whether the incremented rank of the slave station is less than or equal to the number of communicating stations. is judged.

If the number is less than or equal to the number of communication stations, return to step 125,
Repeat steps 125 to 143.

It is executed according to the slave station transmission order. Stella 7al on the other hand
If it is determined in step 43 that the number of communication stations is greater than or equal to the number of communication stations, in step 145 a transmission command is transmitted to the start station, that is, the first slave station in the transmission order.

In this way, only stations with which communication is possible are investigated, and only the address stations set by the user are communicated with. Further, from the investigation of communicable stations, the slave station receives the transmission time from the start transmitting station of the slave station. This communication establishment is executed when the power of the master station is turned on or when the reset button of the master station is pressed. That is, the number of communication stations is increased or decreased when the power of the master station is turned off or when the reset button of the master station is pressed, and when the power is restored, communication corresponding to the added or decreased stations is performed. By doing this, the input/output points of the controlled device of the slave station used by the user are changed, the number of slave stations is increased or decreased, and communication can always be performed at the fastest speed.

Next, with reference to FIGS. 5E and 5F, data reception 1
The following subroutines will be explained. Data reception 1 checks the received data for errors, receives the waiting time if the data is a waiting time, and outputs the data to the sequencer if it is output data. First, in step 147, it is determined whether there is an error in the data previously received by the slave station. That is, COMD shown in Figure 4A (see command table)
The last bit of is checked, and if it is '1', it is determined that there is an error, and if it is 'O', it is determined that there is no error.If it is determined that there is an error, the process proceeds to Stella f151, and the error is determined to be due to an error in the other station. Determine if there is a disconnection.

In Stella f152, disconnection flag On is "1"
When it is determined that there is a separation, the Stella f163 outputs a pressure warning. If it is determined in step 157 that there is no disconnection and the disconnection flag is 0n-0), step 1
At step 59, the counter station's error count is incremented. (Error flags On, Jn, Kn shown in Figure 7)
Increment by 1 for 3 bits consisting of . ) As a result, if the disconnection flag is on or l, step 16 is performed.
In step 3, the alarm of the disconnected slave station is displayed. That is, 2
If there are two or more consecutive errors, an alarm will be output and the device will be disconnected.

On the other hand, if it is determined that there is a disconnection, the previous reception error On indicating that there was an error in the partner station is sent in step 165.
Set the flag. On the other hand, in step 147,
If it is determined that there is no error, the counter Kn is cleared in step 149.

That is, unless there are consecutive errors, the count will not be counted up as an error. Next, at step 151, it is determined whether or not there is an error in the partner station twice in a row based on the previous reception error flag Sn. If it is determined that there is an error in 5n=1, the process proceeds to step 155.

On the other hand, if it is determined that there is no error, the disconnection flag is reset in step 153 and the disconnection is canceled. Next, in step 155, since there is no error in the current reception, the flag Sn indicating that there is an error in the other station is reset. Next, the process proceeds to step 167. stella f16
In step 7, it is determined whether the previously received data is erroneous.

If it is determined that the previous received data is an erroneous pass, the process advances to step 171. On the other hand, if it is determined that there is no error in the previous received data, the transmission disconnection flag Pn is reset in step 169. In Stella 7°171,
A flag indicating that there is an error in the received data is reset in preparation for the next reception, and the error count Mn pit is cleared in step 173. This is data reception 1
This is because the execution of the Sara routine in step 65 means that there is no error in the received data at step 65 since the error has been checked previously. Next step 175
It is determined whether the command is a waiting time command or not. If it is not a waiting time command, the process advances to step 119.

On the other hand, if it is a waiting time command, it is determined in step f177 whether the waiting time data is transmission order data sent from the master station. If the waiting time data is normal, a data reception flag is set in step 183, and the process returns.

On the other hand, if the waiting time data is not normal, the process advances to step 129. In step 179, it is determined whether it is a data transfer command. If it is not a data transfer command, return; if it is a data transfer command, step 1
At 81, input data is output to the sequencer. At step 183, since data reception has ended, a data reception flag is set.

Next, the error processing routine 1 will be explained with reference to the flow shown in FIG. 5G. Error processing 1 outputs an alarm when communication errors occur two or more times in a row and are not normal. First, in step 185, it is determined whether the slave station is disconnected. If it is determined in step 185 that there is separation, the process advances to Stella f191. Stella f185 on the other hand
If it is determined in step 187 that there is no disconnection of the slave station, the received data is incorrect (call) P, L in step 187.

The Mn bits of Mn bits are incremented and the process proceeds to step 189. If it is determined in step f189 that there is no separation, the process proceeds to step 193. On the other hand step 189
If it is determined in pnwl that there is a disconnection, the disconnected slave station is displayed on the alarm 26 in step 19. Next, in step 193, a flag indicating that there is an error in the received data is set, and further in step 19
In step 5, since it is not known which data has an error, the error counter is cleared to a-clear 1 in order to avoid erroneous disconnection due to a reception error. That is, if two consecutive reception errors occur two or more times, an alarm is output and transmission is disconnected.

In this way, the master station transmits data to all the slave stations at the same time, so that switching between transmission and reception can be completed only once. Whether this data has been transmitted correctly can be determined by adding the previous reception status to the input data transfer commands shown in order when the slave station data is transmitted. As a result, the master station can determine whether the data sent to the slave station has been received without error.

To confirm the receipt of data from the parent and child to the master station, the master station adds the reception status to the output data transfer command that is sent to all slave stations at once, so the slave stations on the transfer station side can confirm the receipt of the data. By receiving the command with the ring status added, it can be confirmed whether the transmission to the master station is being performed without error. In other words, it is possible to check whether the sent data has been completely received by the other station when receiving the next data, and all communication stations only switch between transmission and reception once.
Communication is possible with minimum switching and stability time.

The slave station main routine will be described with reference to the flowcharts of FIGS. 6A and 6B.

The slave station transmits the transmission data according to the waiting time from the slave station transmission start station received from the master station upon communication establishment, and after transmission, switches to reception and receives the booter from the parent. at first,
In step 197, initialization is performed to set the receiving mode. This initialization is similar to the initialization of the master station shown in FIG. 5A, so the explanation will be omitted. Next, in STELLA'';f199, a communication establishment process is performed to receive waiting time data from the start station of the slave station until the local station transmits.Next, in step 201, transmission data from the sensor is set, and in step 203, The waiting time is set based on the slave station ranking, and the waiting time from the slave station starting station has elapsed and the waiting time has passed.When the time has elapsed, the ranking HL9 of the slave station with which to communicate is determined in step 205.
Initialize to i0, and in step 207, HL9 is doubled and the value of 7 is set in the parameter Furthermore, in STELLA f209, the data of four input points is transmitted to the master station.In step 213, the order of the communicating slave stations is incremented. Next, in step 215flC, it is determined whether the number of communication stations in the local unit is equal to or less than the number of communication stations. If the number is lower than the communication station, the process returns to step 201.

After transmitting the data on the number of all communication stations of its own station unit, the 0th order Stella f219 enters the receiving state at step 211.
In Ilc, it is determined whether the communication data is communication data from the parent station to the own station.

If it is determined that the data is not addressed to the parent station, the process returns to step 211.

On the other hand, if it is determined that the communication data is from the parent to the local station, it is determined in step 221 whether the received data is a command to establish communication.

If it is a command to establish communication, the process advances to step 265 of the flow for establishing communication with the slave station, which will be described later.

On the other hand, if it is determined in step 221 that the communication establishment command is in error, step 225 is performed to OK initialize the order of the communicating slave stations.Next, step 2
Proceed to step 27 to determine whether the communication station in your own unit is a receiving station.0 If it is determined that the station is not a station that performs communication,
The time is adjusted so that the time is the same as when communicating with Stella f229 h, and the process proceeds to Stella f249. On the other hand, when Stella f221 determines that the station is the one to communicate with, the process proceeds to Stella f231, and an error is detected. It is determined whether the flag is set. Step;! 31, if it is determined that there is an error, then in step 233 the time is adjusted so that it is the same time as when the data was checked, and the process proceeds to step 243.
If it is determined in step 231 that there is no error, COMD and ADR shown in FIG. 4A are executed in Stella f235.
D. DATD.

Zero-order sum setting CRCD, CRC check is performed in step 237. If the result of the CRC check is an error, the time is adjusted in step 239 so that the time is the same as when the address check was determined. On the other hand, if the result of the CRC check is correct, step 241t
Check the address using IC. If the result of the address check is an error, the process proceeds to Stella f243. On the other hand,
If the address is determined to be legitimate as a result of the address check,
In step 247, the process advances to data reception 3 in which data is received.

In step 243, an error processing subroutine to be described later is executed, and in step 245, the time is adjusted so that it takes the same time as the data reception processing.
Proceed to step 49. In step 249, the ranking of the communicating slave stations is incremented.

Next, in step f25, it is determined whether the communication station is one of the local units. In other words, it is determined whether the processing has been completed for all controlled devices connected to the slave station. If not completed, step 227 to step 251
Execute repeatedly. On the other hand, if it is determined in step 251 that all communications within the own station have been completed, the RUN rung is flashed on the stellar f253, and the process proceeds to step 20.
Return to 1. In this way, the slave station grasps the waiting time from the slave station's transmission start station when communication is established, and when it receives data from the parent, the slave station's start station transmits and each slave station follows the waiting time. and sequentially transmit them to the master station.

That is, by providing a waiting time, communication can be performed at the fastest speed.

A flowchart for establishing slave station communication will be described with reference to FIG. 6C. To establish slave station communication, the master station receives a waiting time from the start station which determines its own transmission order, and first, the Stellar F255 receives communication establishment data. Next, in step 251, it is determined whether the received data is a reset command P. If it is a reset command, the process returns to step 191 and the slave station is restarted. On the other hand, if it is not a reset command, step 26
The process proceeds to step 1, and it is determined whether the data is the waiting time data of the own station.

If it is local station waiting time data, the process proceeds to step 225 in FIG. 6B, as in step 259. If it is determined in step 261 that it is not local station waiting time data, the process proceeds to Stella f225 in FIG. 6B; on the other hand, if it is determined in step 263 that it is local station output data,
At step 265Vc, it is determined whether it is a start station transmission command.

That is, up to this point, it is determined whether the command is related to the own station. If it is determined that it is a start station transmission command, the process proceeds to Stella f277; on the other hand, if it is determined that it is not a start station transmission command, the process proceeds to step 267, where it is determined whether or not it is local station waiting time data. If it is determined that the waiting time data is the local station waiting time data, the waiting time data for confirming reception of the local station waiting time data is returned in Stella f213, and the process returns to step f255flc. On the other hand, step 16f! I
If it is determined at fC that the data is not local station waiting time data, the process proceeds to step 269, where it is determined whether or not it is a local station reception command. If it is determined in step 269 that it is not a local reception command, the command P is not a regular command A, so the process returns to step 255.On the other hand, if it is a local reception command, step 1r
At lIfC, send back a reception command to confirm receipt of the reception command,
Return to step 255. On the other hand, the process goes to step f221 and sets the communication stations in the local network, and then returns to step f201. By doing this, it is determined whether or not it is a command to establish communication (2), and the master station receives the waiting time from the starting station of the slave station and knows the timing of its own transmission.

Next, the flowchart of communication establishment reception will be explained with reference to FIG.
First, in step 279, the carrier waits until the carrier runs out. This waits until the carrier runs out in order to prevent the establishment of communication with the next slave station while the data communication with the previous slave station has not been completed. Step 2: If it is determined that the carrier is not being output, it can be assumed that the data communication with the previous slave station has been completed, so in step 281, from the next communication station Determine whether the data carrier is being output.

If it is detected in step 281 that the next data carrier is being output, the Stellar f283 determines whether the first bit of the data is HIGH and the last four bits are LOW. do.

This determines whether the data corresponds to the first 5 bits shown in Figure 4C (these bits are dummy bits and are provided to synchronize before starting data communication). ing. If it is determined in step 283 that it is a synchronous bit, the process proceeds to step 284. When the data synchronization timing is adjusted through these steps and five dummy bits are detected, a HIGH start bit is detected in step 284, so the process proceeds to step 285.

On the other hand, if the start bit is not detected in step 284, it is determined that the data communication was not performed correctly, and the process returns to step 229. In step 285, the /mother 2 meter X is initialized to 0.

Next, wait for 300 cycles at Stella f281 h. This value means that the basic performance of the 8-bit CPU used and discussed is 3.85 B+! Hz, communication speed is 4800
bps, so from these values it is approximately 20
This will result in 0 cycles. In order to synchronize with the start bit, the time is adjusted to a value of one and a half bits, that is, 300 cycles.

At the next step 289, Aki and Mureta @16”
Set the value of

This means that the KTR)G)T bit is @ as shown in Figure 4A.
This is because it consists of 16" bits.Next, in step 291, 1 bit of TRXDT bit is taken in, and in step 293, 200 bits corresponding to 1 bit are taken in.
The process waits for a cycle and adjusts the time, and in step 295, the space and muleta are decremented by 1. This operation is repeated until 16 bits have been taken in. When 16 bits of data have been taken in, it is determined in step 299 whether or not a carrier is present. That is,
If the carrier signal disappears before the stop bit is detected, it is determined that the data communication was not performed correctly, and the process returns to step 281, where the data is restarted from the beginning.

On the other hand, when it is determined in Stellar f299 that a carrier signal is output, it is determined in Stellar f301 whether the next data is a stop bit.

If the stop bit LOW is not detected,
It is determined that the data communication was not performed correctly, and the process returns to Stellar f2';r9, and Stellar f301 is executed again from step 219.

On the other hand, when Stella f301 detects a stop bit, data communication to that station ends, and preparations are made for data communication to the next station.

That is, step 3031: Since TRXDTl is 16 bits, double the byte address by Stella fsos,
In the STELLA f305, two stop bits are detected to determine whether the communication has ended. In this embodiment, two stop bits are added after the TRXDT bit to indicate the end of communication. Step 305
When 2 stop bits are detected in
Return as is. On the other hand, if stop bit 2e is not detected, it is determined in step 30F whether there is a carrier. If it is determined that there is no carrier, it is assumed that the communication has ended and the process returns. On the other hand, if it is determined that there is a carrier, it is determined in step 309 whether the data is a synchronous bit.

That is, dummy data of 1 [5 pits] of the next data is detected. ! [If 5e worth of dummy bits are detected, the process proceeds to step 311. In step 311, it is determined whether it is below the local communication station. If it is below the communication station, the process proceeds to Stella f281, and the steps from step 287 to step 311 are repeated. executed. On the other hand, Stella f311
After 1 fc, if it is determined that data communication has been completed for all communication stations within the local station, the process returns.

By performing reception in this manner, data is repeatedly received from the master station from the number of communication stations within the local station using the minimum number of slave stations (in this example, 4 points for each input and output). By doing this, the number of input/output points of the slave station can be freely selected. In this embodiment, as shown in FIG. 3, input/output can be selected from 4 points, 8 points, 16 points, and 32 points. With this method, even if the number of input/output points changes, when the power is turned on, communication is established, the internal address of each slave station is automatically determined, and the transmission wait time is sent from the master station, so the user can The number of input/output points can be changed simply by setting the local address of the slave station and the number of input/output points.

Next, the data reception 3 routine will be explained in detail with reference to charts 70 shown in FIGS. 6E and 6F.

Data reception 3 determines whether the command from the master station to its own station is a waiting data time or a data output, and if it is a waiting time, it sets waiting time data, and if it is a data output, it outputs its own data to the master station.

In this flowchart, steps 313 to STELLA f339 are the same as steps 142 to 113t of data reception 1 of the master station shown in FIG. 5E, so the explanation thereof will be omitted.

Stella f34111c in FIG. 6F determines whether a reset command has been issued from the master station.

If it is a reset command, return to step 197;
Restart the slave station. On the other hand, if it is not a reset command, the process advances to step 343 and it is determined whether it is a communication establishment command. In the case of a communication establishment command, Stella f in the flowchart for establishing slave station communication shown in FIG.
Proceed to 265. On the other hand, if it is not a communication establishment command, the process proceeds to step 345, and if it is a waiting time data command, waiting time data is set in step 347, and the process returns.

On the other hand, if the command is not a waiting time data command, it is determined in step 349 whether it is an output data transfer command. If the command is not an output data transfer command, return as is. On the other hand, if the command is for output data transfer, the Stellar F350 determines whether the slave station has been disconnected, and if it has not been disconnected, the process proceeds to step 35.
1 outputs the output data and returns. If the slave station is disconnected at step 350, the process returns directly.

The error processing subroutine 2 shown in FIG. 6G lights up a rung in the case of an error in communication, and is the same as the error processing subroutine 1 shown in FIG. Therefore, its explanation will be omitted.

FIG. 7 is a RAM map showing various flags indicated by 70-Tyaert in FIGS. 5 to 6F and used in each control program of the next 11 stations and slave stations. In the figure, PIll, L, and Mll are counters each indicating the number of times the next data received was erroneous.

On, Jn%K11 is a counter that indicates the number of times the communication partner station received data errors. Rn, 5U is a flag used to disconnect a slave station due to reception error or transmission error. This is the 7 lag of the slave station that communicates QnFi control signals. Further, Tn is a flag indicating communication disconnection based on the logic of 9 and Syu.

In addition, according to the applicant's experimental results, l scan time/number of control points was 0.31+@c or less with 64 input points and 64 output points. According to this result, since one scan time is short, input/output control signals can be transmitted to the control device at intervals of 0.3 m@c, and sensor input can be transmitted to the master station. That is, it is possible to transmit control signals almost in real time. In addition, in this embodiment, both input and output points are 64 points, and this system can be connected to up to four sequencers, making the total number of input and output control points 256 points each).
A sufficient number of points can be obtained for general control purposes.

Furthermore, the master station can be directly connected to the sequence controller, and no additional input/output card is required. As shown in Figure 3, the slave station can control the input and output of the controlled device, and is also equipped with protective equipment.

This method does not require a conventional control panel, the control equipment is distributed near the controlled equipment, the slave stations that would otherwise be left behind are standardized, and the cost is lower than that of the existing control panel. I can do it.

AC power supply whose phase is controlled because the controller is located near the controlled equipment! Pass duct (e.g. Kenko Denko's 7 Act Line)
When using the distance fii &
The length of the input/output wiring and power wiring from the control panel to the controlled device is significantly reduced compared to the short length, and the wiring cost is also low, and wiring changes can be made quickly and inexpensively using one-touch connectors. You can.

Furthermore, this configuration can be installed in existing equipment without any changes to the equipment.

This sequence control method using a power carrier path can also be used for real-time control, the number of input/output points of slave stations can be selected, and it is a low-cost total system.

(Effects of the Invention) According to the present invention, the master station transmits data to all the slave stations at the same time, and the slave stations transmit the next data depending on the waiting time for transmission from the master station. Data can be exchanged by switching between transmission and reception at the same time, and it only takes one time to confirm the data stabilization when switching between transmission and reception, which minimizes communication time and can also be used for online control.

In addition, the number of communication stations within the slave station is set, and when communication is established, the master station is notified of this, and the master station specifies the transmission time of the slave station for all slave stations. When it is finished, it switches to reception.

This eliminates the need for confirmation time until data stabilization for reception switching. Since each slave station can have a plurality of communication stations within itself, the number of input/output points can be selected.

Furthermore, even if the number of input/output points is changed, the transmission wait time is specified from the master station when the power is turned on, so the number of input/output points can be changed simply by setting the number of communication stations of the slave station, and there is no need to change the communication format. There isn't.

Furthermore, a three-phase load, a single-phase output, and a DC input can be connected to the slave station, and standardization is achieved as shown in FIG. 3-1, resulting in a low-cost system. In addition, if the slave station of the controller is installed near the required controlled equipment and a path duct is used, the power and input/output wiring will be #! F.

This will result in a significant reduction in rejections.

Furthermore, by standardizing the slave stations, costs can be reduced compared to conventional side control panels.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the sequence control method of the present invention, FIG. 2 is a detailed block diagram of the master station shown in FIG. 1, and FIG. 3 is a detailed block diagram of the slave station shown in FIG. Detailed block diagram, Figures 4A to 4C are formats of data exchanged between the master station and slave station, and Figures 5A to 6G are flowcharts showing control in the master station and slave station. , and FIG. 7 are RAM pins showing various flags used in the control programs shown in FIGS. 5A to 6G. It is. 1...AC power supply wiring, layer station for 3, 5...slave station, 1.
...Controlled equipment, 9. ．． 9. ...Sensor, 11...
Sequencer, 13...Sequencer connection terminal, 15...
- Encoder, 17...Decoder, 19...Serial root-to-rareru converter, 21...Nonorare-to-serial converter, 231 s z3. 1 chip CPU, 2
5. , 25°...power transfer unit, 26...alarm device, 391. 39@t J 9B * 35'4...
Photothyristor. Figure 5B [Stock] □ Figure 5D Figure 5G Figure 5F Figure 6C Figure 6F C [Eng. 5 Figure 60

Claims (4)

[Claims] (1) a power transport path, a master station connected to the power transport path, a plurality of slave stations connected to the master station via the power transport path and transmitting and receiving data with the master station; a controlled device connected to a slave station; a sequencer connected to the master station and controlling the controlled device connected to the slave station via the master station; and a means for superimposing a control signal for controlling a controlled device on the power transfer path, the sequence control system controlling the controlled device using the control signal supplied via the power transfer path, wherein the master station Inquires each slave station in turn, determines the order in which to transmit data to the slave stations that respond, and notifies each slave station of different waiting time data according to the ranking, and determines the data to be transmitted. The sequence control system is characterized in that the master station transmits data to each slave station all at once, and each slave station sequentially transmits data to the master station according to given waiting time data. (2) Each slave station has means for switching input/output points of the controlled device, and the data format when the slave station transmits to the master station is fixed regardless of the number of input/output points. The sequence control system according to claim 1, characterized in that: (3) The sequence control system according to claim 1, wherein the master station has an encoder and a decoder adapted to the input/output specifications of the sequencer so that it can be directly connected to the sequencer. (4) The controlled device is connected to three-phase AC and single-phase AC, the master station and slave stations are connected to the single-phase AC line, and each slave station is connected to the three-layer AC additional protection breaker. 2. The sequencer control system according to claim 1, further comprising circuit protection means for single-phase additional protection.