IS CP340 RS232 module in Siemens S-300 PLC faulty?

[Savannah]

Good Day All:

We have a radiation dose calibrator (measures radioniclide activity) which connects to a CP340 RS232 module on a Siemens S-300 PLC. A custom 'activity dispensing' PC application program (COMECER, Agatha Timotheo) speaks to the PLC to take readings from the radiation dose calibrator and displays it in the user interface. After a series of power failures, we found that no reading updates appeared in the user interface (just 0.000 - no noise indicating any electronic activity). We first thought that the radiation dose calibrator may be faulty. Replacement of the device indicated no change - still no reading updates. A question: With the application control program functioning OK, is the CP340 RS232 module faulty/broken.

The CP340 RS232 module shows the following: SF is ON; TX,RX is showing no 'activity'. Surely, these LEDS should show some 'activity' if the radiation dose calibrator-PLC-PC user interface was functional. We assume standard RS232 communications.

I am not a PLC expert or an electronic professional. Any advice will help!

In Appreciation....

 

[JesperMP]

It used to work, then there were a "series of power failures", and then it didnt work any more.
Can you provide more info about the "series of power failures" ?

The SF lamp means that there is a failure in the CP340 or the configuration. You should go online with the S7-300 PLC and investigate the diagnostics buffer in both S7-300 CPU, and the CP340.

If you exchange the radiation meter, then it is possible that it must be setup with the proper communication parameters. Maybe it is this that is missing.

It is not impossible that the CP340 itself is defective. But 1st step is to see if the diagnostics buffers reveal anything.
I also think you should contact the original programmer of the S7-300 program.

NB. I find that random underscore, bold, and italic makes a text much less readable.