Short of cycling power, what might cause a PLC-5 (5/20C) to lose its IP address?
I know on power up, the PLC must query the BootP server to get its IP address. Is there anything else?
We had a PLC lose its address this afternoon during a power sag (about 1 second). Our system is set up so that the PLC should never have seen this sag - it is on a UPS that should have kept power to it for almost 30 minutes! Despite the UPS, I suddenly had no Ethernet communication with this PLC, and I had to restart the BootP server to fix it (long story why that wasn't running . . . )
We will certainly be verifying the operation of the UPS the next time the line is down, but in the meantime if anyone has any thoughts, I would appreciate hearing from you.
Thanks,
Marc
I know on power up, the PLC must query the BootP server to get its IP address. Is there anything else?
We had a PLC lose its address this afternoon during a power sag (about 1 second). Our system is set up so that the PLC should never have seen this sag - it is on a UPS that should have kept power to it for almost 30 minutes! Despite the UPS, I suddenly had no Ethernet communication with this PLC, and I had to restart the BootP server to fix it (long story why that wasn't running . . . )
We will certainly be verifying the operation of the UPS the next time the line is down, but in the meantime if anyone has any thoughts, I would appreciate hearing from you.
Thanks,
Marc