Siemens S7-300 PLC blink light command

Does anyone know if there is a way to identify an S7-300 PLC by blinking the LEDs? I'm working in a development lab and we have a bunch of processors and aren't sure which is which right now and are looking to identify them.

On a related note, where is the best place to find the MAC ID the Processor or CP module is using. Another engineer I'm working with says that Siemens allows the MAC ID's to be reset to follow the one in the project, so using MAC ID won't be helpful in this case, but I'm looking for it for future reference for systems where they're not doing thaat.

Any assistance appreciated...

-Greg

Yes, there is a "blink" function for anything that is connected via Profinet.
In the Simatic Manager, you open the hardware config and then PLC .. edit ethernet node.
In the dialog there you can scan for reachable nodes. When a list of found nodes appear, you can select one and activate the blinking of some of the LEDs on the module.
Play around with it and you will quickly figure it out.

About the MAC address. I havent heard that it could be resetted. But even if it is possible, why would anyone do that ?
Usually the CPU, CP or IM has the MAC address printed somewhere on the cover.

Flash and MAC ID

JesperMP...

Thanks for the tip on blinking the lights...was able to find it.

Comparing the MAC ID's against what is printed on the module, it does look like they've been changed at this site. As to why they would do that, my colleague said it had something to do with a request from IT...not sure exactly the story behind the IT request though...happened long before I got here...

-G

Maybe has to do with some comms based on ISO protocol. This is based on the MAC adresses rather than IP addresses.