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Communication between PLC and PC #495
Description
Hello,
I am trying to establish communication between a non-optimized DB in my PLC and a PC.
On the PC I am using the Python programming language with a Snap7 library.
The PUT/GET function is activated on the PLC.
Communication must be very fast (~100ms).
The PLC is a 1513F-1 PN with the following part number: 6ES7 513-1FL02-0AB0 and this firmware version: V2.9
The cycle time of the PLC is around 40-60 ms.
Unfortunately, the evaluation is not stable.
For example:
We have physically mounted two triggers. One trigger goes to the PLC
The other trigger goes to a camera, which triggers if the trigger is interrupted. The images are retrieved from the PC via a Python script. This also works so far.
The PC counts up 1 for each photo and sends the value to the PLC. Unfortunately, not all values written by the PC arrive at the PLC. In other words: 1000 triggers sent to the PC --> 997 triggers arrive in the PLC
Does anyone have any experience as to why this could be and can they please help me?
Activity
nikteliy commentedon Mar 28, 2024
Such behavior can have multiple reasons, and the python-snap7 library is far from being the first one. In any case, without details, it's difficult to suggest anything.
I would start by checking the PLC settings. For example, this may be related to the short cycle time. You might want to try increasing it.
