Drive and PLC Communication Loss

[Manoj M]

Hello Experts,
I have Siemens 315-2PN/DP and drive from third party. Drive is sitting on Profinet network and it is working fine. Now the customer wants to show me a signal for communication loss on HMI.
There is one register in drive which keeps updating (by the drive) and resets to zero after overflow. My concern is to monitor this register and if it didn't update in 2 seconds then I have to raise the loss of communication bit. Can somebody suggest me the simplest way of doing this.
Any help in this matter will be highly appreciated.

Regards
Manoj

 

[osmanmom]

i don't have any answer for your question,

just merry go round found this link,

hope this will give you some idea

 

[mk42]

Assuming also a Siemens HMI, and all you want is a text alarm?

The easiset way may be to use the system diagnostics of the PLC. Look up Report System Error if you are using Simatic Manager, or System Diagnostics if you are using Portal. No bits necesary. Once you enable this, the PLC automatically creates alarm messages for most hardware and network errors. Module pulled out of the rack? Alarm sent to the HMI. Lose communication to Profinet/bus device? Alarm sent to the HMI. These alarms are based on the text names you give the devices in the HW Config, so if your drive is called Drive17, the alarm text won't be much help. If your drive is named ConveyorSection3Motor, then the alarm will be much easier to read.

If you do want a communications bit (for alarming, for animation, etc) or if you have a 3rd party HMI that doesn't support PLC based alarms, one way to do this would be to read the system status lists using SFC51(I think?). You can bring up the diagnostic status of any individual device, or of the whole PN network at once, or the LEDs on the PLC, or about 100 other things.

 

[Manoj M]

Thank You very much for your suggestions.
I would like to state one more thing which I forgot to mention in my first post. There are two drives which are sitting on Profinet network. I do appreciate that with SFC51 I can have the diagnostics for Profinet network but the problem is if one of the drive is not communicating then SFC51 is giving me a BUS2 fault which is a general fault for Profinet network. I need to show for example Drive 1 is on fault or Drive 2 is on fault.
I hope it makes sense.

Regards
Manoj

 

[mk42]

If you look at the LEDs then yes, all you will see is the bus fault. However, as I said, there are lots of system status lists available, including one that has the status of every PN device. I'm not in front of my manuals, so I can't look it up at the moment, but you should be able to find it in the S7 help file.