Powerflex 400 Ethernet Issue

OK, let me paint my picture before I get to the question. We have a pumping system that is connected to the customer's wireless Ethernet network. The customer supplied the IP addresses for 1 HMI (PV+), 2 drives (Powerflex 400), 1 PLC (CompactLogix), the radio, and a separate device in another panel. We have a 6 port switch in our panel connecting them all.

Recently, one of the drives' 22-COMM-E has started "faulting". When it happens, we get the following lights:

Port: Steady Green
Mod: Flashing Green
Net A: Flashing Red
Net B: Off

It will stay in a fault condition (actually the PLC program is causing the "fault" as it is monitoring the IO module's FaultCode) for several minutes, then re-connect to the network. This is causing problems, as you could imagine.

So if I am interpreting the manual correctly, this looks like a case of too much network traffic, or too slow. The RPI for the drives is set to 400ms. My question is, if there is a Gateway configured in the PLC, and the gateway is remote to the panel on the wireless network, does the drive's ethernet traffic have to go out the PLC, through the wireless, to the gateway, and back through the wireless, to the drive? Or will the packets stay local to the switch in our panel? Would further increasing the RPI alleviate the problem?

As always, Thank you in advance.

That 6 port switch needs to be a managed switch to prevent Ethernet/IP broadcast traffic from beating up all the I/O devices on the network.

The switch should have at least the following features:
-full duplex capability on all ports
-IGMP snooping

and these features are recommended, but not required:
-SNMP
-port mirroring for troubleshooting
-VLAN
-wire speed switching fabric (each port can handle the maximum rate of the network.)

It is not a managed switch. It's an N-Tron 306TX. This project has been installed for a couple years, and has only recently developed this problem.

My question is, if there is a Gateway configured in the PLC, and the gateway is remote to the panel on the wireless network, does the drive's ethernet traffic have to go out the PLC, through the wireless, to the gateway, and back through the wireless, to the drive?

Click to expand...

To answer these questions, without a managed switch information goes everywhere, your data will go all over your network until TTL expires or the information is consumed (I think).

jedft said:

It is not a managed switch. It's an N-Tron 306TX. This project has been installed for a couple years, and has only recently developed this problem.

Click to expand...

Well something has changed then. Without a managed switch, figuring out which cable has degraded or which device is sputtering or which port suddenly has more traffic and from where is going to be difficult.

I would have to defer to others with more experience on how to go about diagnosing the problem further.

We are quoting other work in this panel and will have to upsize the switch anyway, so I'll make sure it's managed. For now, unplugging the HMI when we leave seems to take care of the problem. Besides the normal HMI traffic it is also updating the PLC's time once a second. Why? Don't know, but it won't be doing that for much longer!

I have ran into this problem a few times.

As said by others..

To much traffic... Power Flex drives are some of the worst culprits... Bad connection...Jack on PF drives seem to be real touchy so cable connector has to be perfect... Bad Comm card on drive... This is the one that bit me the last time... Aparently AB had a bad batch get in the field...

In my experience a managed switch when using powerflex drives is a must... The drives just spout to much data not to be managed.

So any suggestions on a managed switch? I need 8 ports, that's pretty much the only requirement. There are about a million of them out there and I'm at a loss as to which one to use. Right now I'm looking at a Phoenix Contact version of a "lean managed switch" that has "default activated IGMP Snooping and IGMP Query Functions for easy use with Ethernet/IP" The part# is FL SWITCH LM 8TX-E. Anyone have an opinion on that switch?

No particular experiences with that switch, we use Hirshmann and Moxa here. I've taken a real liking to Moxa lately.

However, as far as unmanaged switches go, as well as the rest of their products, I love Phoenix Contact. Great company, and I would not hesitate to give their managed switches a go around.

If you like the N-Tron, then use them. Just order the 500 series with the advanced firmware option. I have had good luck with those as long as you do not get into the more advanced features, like redundant communication paths (a ring setup). N-Tron seems to have issues with these more advanced features and EtherNet/IP (CIP). Every once in a while the ring will reconfigure (could be weeks, months, days or even minutes) and that will cause all your CIP class 1 (your I/O connections) traffic to drop. Which is not a pretty sight during production.

Darren