SIEMENS S7-1200 Run status bit?

[quadPLC]

Does anyone know if the Siemens S7-1200 family of processors has a register I can watch to see if the processor is in run mode?

We have a counter that increments right now, but it'd be more convenient for my current project to just have a bit or word with the processor's current mode.

I didn't see anything in the System/Clock memory registers, unfortunately.

 

[boneless]

Enable the use of clock memory byte, and check if it is alternating.

But then again, how are you going to check if the PLC is not running? Monitor from a panel or a remote PLC?

 

[Geospark]

Look up the LED instruction under Diagnostics instructions...under Extended instructions. You can monitor the status of all the LEDs on the front of the S7-1200.

Set the LADDR parameter to the Hardware Identifier of the CPU. Set the LED parameter to 1, which is the RUN/STOP LED. The Ret_Val output should then have a value of 2 for RUN or 3 for STOP.

As boneless has pointed out, you will have to be able to read this value elsewhere, such as a HMI, SCADA or 2nd PLC.

G.

 

[quadPLC]

@Geospark: awesome, that should work well!

We are using S7net (https://github.com/killnine/s7netplus) and a Windows service to occasionally check on the status of field equipment. It just does a one-off check every few minutes, no need for an OPC server.

That's kinda why it'd be nice to not watch a heartbeat. With a heartbeat, you have to hit the PLC twice. Once to get the initial value, again to make sure it changed.

 

[mk42]

QuadPLC,

I'm curious, did this actually work for you? In my experience, the PLC would not execute the block if it is in stop, so the tag wouldn't update, and so the HMI would continue to show 2, not 3.

 

[quadPLC]

QuadPLC,

I'm curious, did this actually work for you? In my experience, the PLC would not execute the block if it is in stop, so the tag wouldn't update, and so the HMI would continue to show 2, not 3.

I haven't done this yet, though I will be sure to post back once I do. I tend to think you're right but it's worth a shot!

I should get around to adding that logic in within the next 2-3 weeks.