Hi,

If our rack contains DI modules without diagnostic capability, for which I believe one would use diagnostic interrupt OB82, is there any other way in PLC code to identify the faulty DI module?

Thank you!

Dan

Hi,

PLC does not accept faulty modules. Even though no interrupt capability, CPU identifies it and goes to stop. For these modules, go to online in hardware configuration. Or u can use  module information [Right click CPU]. Also there are fault SF LEDs on every module for this purpose.

Hi Sachin,

Thank you for the response.

I should've add more details to my post. We would like to use "Fault/Healthy" DI module information captured in the PLC and transmitted to SCADA.

Again, the DI module has no diagnostic capability.

I was thinking to use SFC51 (or any other way one would advice ...) to read the system status list and get the fault/healthy bit about the DI module (we do not need detailed diagnostic information) and then SCADA will have as well access to this information. I do not know if SFC51 would work...

Kind regards,

Dan

Hi,

You can use SFC51 with following parameters:

Partial list extract with SSL-ID W#16#0C91:

INDEX :

- S7-400: bits 0 to 14: logical base address of the module, Bit 15: 0 = input, 1 = output.

- S7-300: bits 0 to 14: any logical base address of the module, Bit 15: 0 = input, 1 = output.

Hi Koiri,

You've also the possibility of Wirebreakage in order to be sure that the DI and cable are OK,