S7-300 SFC51 Module Diagnostics

Hello,

Does anyone have a well tested code that could be shared, using SFC51 to perform Diagnostics for S7-300 IO modules and ET200s modules?

Regards

Hi,

If you invoke the 'F1 Help' for SFC51 in Step 7 and drill to the very bottom there are a couple of links there to an example for detecting IO point/module faults.

I do have a document of sorts that I made for someone on here years ago for using SFC51 to detect missing/faulty PROFIBUS slaves if thats any use?

I think it takes a lot of work, but it IS possible.

If you find the PNIODIAG library you will get code and HMI templates. As far as I remember the fault diagnosis is detailed enough to point to the faulted module.
However, PNIODIAG is only for PN or DP slaves. Not modules in the S7-300 rack.

I have resorted to simply enabling the web-server in the PLC CPU, so that the end-user gets easy access to the diagnostics buffer. To interpret the diagnostics buffer entries is not straightforward, but the contents can be copied to a file that can be sent to an expert (you ?) for analysis.

Dear krk,

I have used in the past SFC51 to detect DP slave failures.
What I am talking about is getting diagnostic data of an analog module, down to a level of reporting wire breaks, no PS to the module and so on. I have seen it being done this way, and I thought that maybe someone has used in the forum. I will try to make it and If succesful I will post the code.

Regards

I would be interested if you figure it out

What diagnostics are you looking to perform? Display a message on the HMI screen in case of some error (broken wire/short cicuit, etc)?

There is some built in functionality to do this in Step 7, called Report System Error. Assuming you are using Simatic Manager, you can activate this from the HW Config by selecting the CPU, and then going to Options -> Report System Error. A bunch of configuration is possible, but the only thing you NEED to do is hit the generate button at the bottom of the new window.

It will automatically create a PLC alarm for any diagnostic event in the system, whether its a HW error, a network error, or a program error. It generates an FB and inserts it into a few different OB's automatically. The only trick, I think, is that it might only work with a Siemens HMI. I'm not sure if controller alarms can be read by other vendors systems.