All geek questions in one place

Improving performance with OPC tags

I work with a PC-based software package called Think'n'Do, created by Phoenix Contact. It processes in real time, reads the inputs / control logic / write outputs, which are performed in a maximum of 50 ms. We have an OPC server that reads / writes tags from the PLC every 10 ms. There is a long delay in writing a tag in the PLC and reading the recorded value (Thinksn'Do (50 ms)> OPC server (10 ms)> PLC (10 ms)> OPC server (10 ms)> Think'n'Do (50 ms)), this process takes up to 6 seconds to complete, when in my math it should only take 130 ms.

Any ideas on where to look or why it might take a lot longer would be helpful.

+3
source share
4 answers

It depends on how the OPC client is configured to output data. When you sign up for a group in OPC, you can specify the refresh rate. By default, it can be 1 or 5 seconds, depending on the OPC client. There is also a limitation on which the OPC server can set the frequency of updated data. This only applies if the OPC client subscribes to data change events.

, , - / OPC-. . OPC, OPC- , , ​​Think'n'Do - PLC/.

OPC , , OPC Quick Client. TOP Server : http://www.toolboxopc.com/Features/Demo/demo.shtml. TOP Server OPC Quick Client. OPC- , . OPC-, , - ICONICS ( OPC Data Spy), : http://www.iconics.com/support/free_tools.asp.

OPC-, , . , ​​. , ( 6 ).

+5

, OPC-. OPC , , , . OPC- , OPC- OPC-.

+3

( -), , ( ), , .

() → OPCServer- > PLC- > OPCServer- > App (). ( ).

(Write) → OPCServer- > PLC- > OPCServer- > App (Done).

, ,

, , . Allen-Bradley PLC , - . , .

+1

: OPC, OPC, OPC- .

:

  • OPC. OPC, OPC, ( 100 1 , ). , ? DCOM .
  • OPC Client. OPC Client (, - OPC Foundation OPC Server), , . , .
  • OPC server - Some OPC servers have diagnostic tools. Turn on these features and see what time it is when records actually occur and what time reading actually takes place. If you can answer these questions, you can probably determine if the delay is from the PLC or OPC server. Also, pay attention to the CPU utilization of the OPC server, if you notice that it is using more CPU than usual, this probably means that the OPC server is loaded, which can degrade performance.
  • Others. Finally, check the PLC, the network is working correctly.
0
source

Source: https://habr.com/ru/post/1696643/

More articles:


All Articles