OMRON PLC ethernet network overload

[FET_Destroyer 1]

Hi Guys, My company is trying to get real time status of all devices. When I arrive to the company most of the PLC are already connected to the network by EIP21 or ETN21. But they are connected to the same network as computers, laptops, etc. Right now we have some servers collecting data with cx-server, another servers with custom applications using FINS protocol and/or sockets. We have been finding some some problems in the CX-server that can be related with network overload, a lots of comm_failure on cx-server. Do you guys have any tips? Maybe connecting all PLC's to a separated network, isolate from computers and laptos solve the problem, I don't know, even the IT guys don't know what to do :s Any help or tip will be appreciated. Regards

[Crossbow 295]

The automation equipment should be on an isolated network. And there should not be a single hub in it, only switches. Switches learn what devices are on what ports and only forward traffic to the right ports. Also, have IT consider VLAN as a way to segment the automation equipment from the rest without actually rewiring the network.

[PMCR 66]

Here are some other things to consider: 1. The PLC is given a finite amount of time per Scan to service communications. By default, this is 4% of the previous scan time. That can be a small time slice. In the PLC Settings, on the Peripheral Services tab, you can allocate more time per PLC scan for comms. Uncheck Default, and put 50 in 'set time to all events'. This will allow up to 5.0 ms per scan for comms. But will also extend the PLC scan time by up to 5 ms. I would also consider using Wireshark to determine the actual response time of the PLC.

[FET_Destroyer 1]

Hi PMCR, I'm already using the wireshark, but there is something strange. I made a search, without filters, then I filter by a certain kind of IP, which is the IP from the PLCs, and I cannot find any. Maybe Im doing this wrong, or maybe wireshark is wrong. I then filter by TCP and UDP independently and still cannot find anything, I think I'm doing this wrong on wireshark.

[PMCR 66]

Are you running Wireshark on the same PC as the data collection application?If so, make certain that the correct port is being monitored.If Wireshark is on a different computer, you need either a managed switch with Port Mirroring or a true old 10 Meg hub. A standard Ethernet switch will not allow data packet snooping unless Wireshark is on the same PC as the application communicating with the PLC.