date: 2021/8/31
Communication between the PLC and the V/TS series is slow.
To speed up communications, try the following method.
[When creating screens]
When creating screens, consider the following points to improve the communication speed.
<PLC device memory allocation>
Consecutively allocate the PLC device memory addresses that are used for the same screen.
The cycle time* on the V/TS series can be shortened by reducing the number of blocks to access to the PLC.
* The "cycle time" is the time required to show the screen, which is stored in internal device memory $s132.
<Process cycle>
Change the [Process Cycle] for each part according to its usage.
Example: [Process Cycle] in the [Num. Display] dialog on the V-SFT-6
| High Speed | |
| Real time display according to data transition in the PLC | |
| <Update timing> | |
| Every cycle | |
| Low Speed | |
| Slow display update for data transition in the PLC The display will be updated only when data is written through a keypad on the V/TS series. |
|
| <Update timing> | |
| - Once in several cycles | |
| - First cycle when the screen is opened | |
| - Read area "n + 1" bit 15 OFF → ON (at the leading edge) | |
| Refresh | |
| No data transition in the PLC | |
| <Update timing> | |
| - First cycle when the screen is opened | |
| - Read area "n + 1" bit 15 OFF → ON (at the leading edge) | |
* For details about how to check Read area, click here.
<Macro>
When the macro function is used, reduce the number of write times into the PLC in the macro.
The smaller the write times, the faster processing speed can be obtained.
Example: MOV (transfer) command
Line No.0 D200=$u200(W)
Line No.1 D201=$u201(W)
Line No.2 D202=$u202(W)
Line No.3 D203=$u203(W)
Line No.4 D204=$u204(W)
When the above is set, write operation to the PLC is performed five times.
↓
BMOV (block transfer) command
Line No.0 D200=$u200 C:5(BMOV)
When the above is set, write operation to the PLC is performed once.
<Buffering area>
V8/TS series
Select [System Setting] → [Buffering Area Setting] → [Basic Settings] tab, select [Use ReadArea], and set the memory of read area "n + 3" and later as sampling data device memory.
When [Specifiy individually] is selected, allocate device memory addresses consecutively wherever possible.
The cycle time* on the V/TS series can be shortened by reducing the number of blocks to access to the PLC.
* The "cycle time" is the time required to update the screen, which is stored in internal device memory $s132.
V7 series
Select [System Setting] → [Buffering Area Setting], uncheck [Memory Designation], and set the memory of read area "n + 3" and later as sampling data memory.
The cycle time* on the V series can be shortened by reducing the number of blocks to access to the PLC.
* The "cycle time" is the time required to update the screen, which is stored in internal memory $s132.
[Others]
The condition can also be improved as described below.
<Baud rate>
When the V/TS series is connected with a PLC via serial port, increase the communication speed (baud rate). When changing the baud rate, be sure to change the settings on both the V/TS series and the PLC.
V8/TS series
Setting location: V-SFT-6 editor [System Setting] → [Hardware Setting] → [PLCx Properties]
V7 series
Setting location: V-SFT-5 editor [System Setting] → [PLC Communication] → [Communication Parameter]
<Scan time>
Shorten the scan time using the PLC ladder program.
<When multiple temperature controllers/inverters are connected>
When multiple temperature controllers/inverters are connected, activate the communication with all stations.
This eliminates recovery confirmation accesses to the stations where the communication is down.
<Ethernet>
When using an Ethernet compatible PLC, use Ethernet communication instead of serial communication to speed up communications.
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