DeviceNet Trouble

jhweppler

I am running an IRB4400 IRC5 based system and I'm having 2 major issues with the system's DeviceNet network. The 2 issues may or may not be related.<?: prefix = o ns = "urn:schemas-microsoft-com:office:office" />

 

Some Background: There are six DeviceNet Units on the network all together including the one in the robot cabinet, a MAC Bus controlling a bank of air valves, and 4 other Horner Electric Remote I/O Units. Two of the Horner Electric units are setup in the system and connected to the network but are not currently being used. The network has been scanned using a certified DeviceNet Network meter/scanner to rule out any electrical/wiring issues. The units are currently setup for change of state but have been run as polled for a while when trouble shooting this problem. The issues seemed to be the same for both change of state and polled. The system is run 8-10 hours a day and powered off over night and over weekends.

 

1st Problem: Once in a while (on average 0 to 4 times a month) when running the system communication is lost with the devicenet unit in the robot cabinet causing the system to enter a failure state. When I open the cabinet after one of these failures there is a red light on, on the DeviceNet unit. This can be fixed by power cycling either the entire system (ie robot controller and othe controller) or by unplugging the unit from the network and plugging in back in while the system is still running. I can't seem to figure out why this failure is occuring in the first place. It seems to happen quite randomly, never at the same time in the cycle and somtimes even when the system is in a stopped state (although there are still rapid tasks running and polling various signals associated with the DeviceNet Units)

 

2nd Problem: Occasionally (0 to 5 or 6 times a month) on startup of the system the DeviceNet Network fails to initialize correctly causing communication errors with all of the DeviceNet Units. The NS light on all of the units either flashes green and doesn't stop or it stays off and doesn't turn on at all. Power cycling the system doesn't solve this problem. Once the network fails to initialize, it keeps on failing until I take the following steps: Shutdown the system. Unplug all of the DeviceNet units from the system. Unplug the power from the unit in the robot cabinet. Turn the system on and let it boot up (without any of the units connected). Once booted up Shutdown the system again. Hook up the power to the unit in the robot cabinet and connect it back to the network. Turn the system back on. Once the unit in the robot cabinet is initialized (the MS and NS lights are both green and on solid (not flashing)) I plug the rest of the units back into the network. This problem only ever happens on the startup of the system. It also seems to happen in spurts. It may happen 3 or 4 times in one week after being error free for over a month. To prevent this problem from occurring we have left the system running 24-7 without shutting down which seems to work but wastes too much electricity.

 

Has anyone else experienced this sort of random errors with DeviceNet? Any help with either of these problems will be VERY GREATLY APPRECIATED. If anyone knows of any DeviceNet Guru's PLEASE point them in my direction.

 

Thank You.

Robot_killer

hi

 

I had a problem (do not see all I/O units) with a PLC i used adress 10 and 11,  i changed for 10 and 20. it's work.