Hello, I am having Ethernet network crashes on an automation line that have got me puzzled. The system is divided into two parts, each has a PLC panel with the following:
Panel 1
CompactLogix L35E with an ENBT and a SERCOS module on the 1768 bus.
2 MOXA managed switches
18 Ethernet modules mapped in the PLC, and 2 HMIs (FTViewME on a VersaView)
Panel 2
CompactLogix L43
2 MOXA managed switches
12 Ethernet modules mapped in the PLC, and 1 HMI (FTViewME on a VersaView)
Network IP addresses are all 131.9.10.XX, and the two panels are linked via one cable. Each MOXA switch has IGMP snooping enabled, with the last port having priority. The last port on switch 1 connects to the PLC, and the last port on switch 2 connects to switch 1. Ethernet modules range from Fanuc robots, Banner safety controllers, weidmuller IO blocks, Numatics manifolds, CNC lathes, and PLC to PLC comm. All devices have the PLC as their comm target.
Here's the problem: Network is stable up and running. If you connect your laptop to the network and the third octet of the subnet mask is not 255 (ie your subnet is not 255.255.255.0) the entire network will crash and all devices lose comm to the PLC. I poll enet module status via GSV with diagnostic code that runs periodically, and see every device drop out. (Disabling the diagnostic code does not alleviate the problem.)
None of the ENBT processors are pegged in % usage. The online diagnostics of the MOXA show no excessive traffic or comm errors on any ports, and keep the multicast traffic in check. No connection limits are exceeded. I'm totally clueless as to what is wrong. Does anyone have any advice that might help? I'd greatly appreciate it.
Panel 1
CompactLogix L35E with an ENBT and a SERCOS module on the 1768 bus.
2 MOXA managed switches
18 Ethernet modules mapped in the PLC, and 2 HMIs (FTViewME on a VersaView)
Panel 2
CompactLogix L43
2 MOXA managed switches
12 Ethernet modules mapped in the PLC, and 1 HMI (FTViewME on a VersaView)
Network IP addresses are all 131.9.10.XX, and the two panels are linked via one cable. Each MOXA switch has IGMP snooping enabled, with the last port having priority. The last port on switch 1 connects to the PLC, and the last port on switch 2 connects to switch 1. Ethernet modules range from Fanuc robots, Banner safety controllers, weidmuller IO blocks, Numatics manifolds, CNC lathes, and PLC to PLC comm. All devices have the PLC as their comm target.
Here's the problem: Network is stable up and running. If you connect your laptop to the network and the third octet of the subnet mask is not 255 (ie your subnet is not 255.255.255.0) the entire network will crash and all devices lose comm to the PLC. I poll enet module status via GSV with diagnostic code that runs periodically, and see every device drop out. (Disabling the diagnostic code does not alleviate the problem.)
None of the ENBT processors are pegged in % usage. The online diagnostics of the MOXA show no excessive traffic or comm errors on any ports, and keep the multicast traffic in check. No connection limits are exceeded. I'm totally clueless as to what is wrong. Does anyone have any advice that might help? I'd greatly appreciate it.