Serial Communication Issue Between CoDeSys and PLC, with log

Hi everyone,

I'm trying to go online with an IFM PLC over a serial connection, using CoDeSys. Things were working fine for a while; I managed to upload a program to the PLC, and it is currently running on the PLC. However, I am now no longer able to connect to it over serial.

I repeatedly get Communication Error #0. I've tried using a different laptop, I've triple-checked all connections, I've switched comm ports and baud rates and am still receiving the error. I also used a line monitor to observe the serial connection, and observed that the received transmissions from the PLC appear strange. See the image below for details.



Any help is greatly appreciated! Thanks

If you not already have it then download the "Downloader" software from the IFM support site.

Use the "Downloader" software to try to connect. This software can scan at different baudrates and identify the unit.

Thanks MrQ. I tried using the IFM Download program, and it also couldn't connect at any baud rate or protocol.

I also tried a different serial cable, and a different PLC. Same problem. At this point, it must be an issue with my wiring. I'm going to try rewiring everything from scratch and retry. Meanwhile, if anyone has any ideas from that log, please let me know!

Thanks

From my experience of playing around with the CoDeSys 2.x protocol to make my own PLC command shell, I can tell you the RX data is garbage and after several attempts CoDeSys stops trying to connect.

I've tried using a different laptop, I've triple-checked all connections, I've switched comm ports and baud rates and am still receiving the error.

Click to expand...

Were you using the same "Keyspan USB serial adapter"? It might have caused the problem. You should try some other device.

i see 57600 and 115000 In the report.
check the baudrate in the communication under online.

I ended up never resolving this problem, and instead wired in USB. USB > Serial; communications are now reliable and fast.

Any time I've seen replies from the controller that were mostly 0xFF, it meant the controller was transmitting at a slower serial data rate than I expected.

That matches shooter's note that both 57600 and 115200 data rates appear in the configuration log of the USB converter.

Glad you got it sorted out !

iam facing a problem like "communication error (#0):logout performe"in codesys
during communicate with abb(ac500-pm554-t)
i unable to find problem, any one can help me