DeviceNet Configuration Parameters Lost

[harryggianakis]

One of our PLC control systems lost its Device Net configuration parameters when we performed a scheduled plant electrical shutdown. We had to reconfigure the parameters, but that cost us 1/2 day's worth of time. This does not happen every time we have a shutdown, only once thus far. Any suggestions on what could have caused these parameters to get deleted would be greatly appreciated. Thanks in advance for any help that you can provide.

 

[Paullys50]

Were changes made to the network?

 

[harryggianakis]

This problem occurred at one of our plants, but (as far as I know) no network changes were made

 

[Paullys50]

Until you get more details, I would speculate on human error. Wouldn't be the first time a network got wiped because someone didn't understand DeviceNet.

Previous life had a customer that brought in someone else because they were cheaper to do some work, they wiped DevieNet networks on multiple MCC's when they tried to do an update. They were down for 2 days before they called us in for help.

 

[jstolaruk]

Every bit as important to backup the scanner configuration with RSnetworx and keep it together with the PLC and HMI source.

 

[harryggianakis]

Paully's 5.0... They claim that the problem occurred after a scheduled plant electrical shutdown (and subsequent power-up of the system). As such, is it possible that something was set up/configured incorrectly in the system (or some combination of things occurred) to cause this problem on power-up?

jstolaruk... Very good advice on ensuring that backups are made of the scanner. I will definitely pass that information along to the site.

 

[Ken Roach]

You're going to have to do some more digging to figure out exactly *which* devices got reconfigured or misconfigured.

I've seen a couple of different "we powered down and everything went pear-shaped" events.

One was with MCCs with the original generation of E3+ overload relays. The DeviceNet address and data rate on those was set via software rather than a dial switch, but it (and several of the important configuration parameters) didn't take effect until power was cycled. Somebody thought they were being helpful by doing a "Download All" during commissioning, which was all fine and dandy until power was cycled and all the overload relays started up with the default parameters in them, and all addressed to Node 63.

Others have included the "Automatic Device Replacement" feature, where the configuration parameters for slave devices are stored with the Scanlist in the Scanner. Folks would save the Scanlist and all the ADR-related data *before* they commissioned and configured the system. On the next power cycle, weeks or months later, the Scanner dutifully over-wrote the active configuration with the stored one.

And in at least one circumstance, the Scanner was found to have been set back to defaults. Turns out the shutdown included quite a bit of welding on the machine frame, and it's so much trouble to actually move the ground clamp......

 

[harryggianakis]

Ken..., Thanks again for the input on possible causes of this problem

I will ask them which devices needed to be reconfigured