ProfiNet GW cannot read 320 Bytes

iotmon · Post by **iotmon** » 21 Jan 2021, 12:36

Hello everyone!

We have the problem right now, that we can only read (including) 315 Bytes with our ProfiNet GWs. If we read after that with piTest, we can only see zeros, no matter what we write on those addresses. We tested several modules, everywhere we tested we get the same result.

Does anyone have an idea what the problem could be or where I could start digging deeper? Unfortunatly I have limited access to the PLC, so I wanted to start looking into the problem on the RevPi side first.

Thank you all so much and stay safe and healthy!

Post by **dirk** » 21 Jan 2021, 13:27

Hi iotmon, have a look at the user manual of the device here:
https://www.kunbus.com/profinet-irt-gateway-module.html
The IO data is divided into a cyclic and an acyclic part.

: 2021-01-21 13_26_46-Gateway Component for PROFINET.png (33.43 KiB) Viewed 3118 times

iotmon · Post by **iotmon** » 22 Jan 2021, 10:32

Hi Dirk,

yes, I read that and that is what gets me worried. As far as I know we write all 317 Bytes in the form of the acyclic data exchange. That's why I don't understand why we get 315 Bytes and the other 2 Bytes we want to read and that are transferred just as the other ones are not visible.

Greetings

iotmon · Post by **iotmon** » 10 Feb 2021, 20:39

Hi everyone,

In the end it was a problem on the PLC which I had no access to. As that was solved, we had no problems reading beyond the 315Bytes described in the problem.

Greetings!