Communication Fault

[damper 0]

I’m having a problem with a FlexLogix (I believe). Here is how the layout goes. I have a FlexLogix linked to a PanelView Plus 600 in cabinet one. A SLC 5/05 linked to a PanelView 550 in cabinet two and a SLC 5/05 in cabinet three. I needed all three PLCs to communicate to trade various information about a bottle line. I installed a five port ethernet switch in cabinet one with the Flex. From the Flex to the switch, switch to the PanelView Plus, switch to SLC in cabinet two (Short distance), switch to PanelView 550 in cabinet two (Short distance) and switch to SLC in cabinet three. I’m using the Flex as the brains so-to-speak; I am using MSG instructions to read a write to the SLCs. Well, I ran into a problem the first time I put this project into motion. The SLC in cabinet two communicated well with the Flex but, the PanelView 550 would not communicate with its node. So I’ve installed a second switch in cabinet two. Now, SLC and PanelView 550 in cabinet two are linked by the second switch and switch one is ran to switch two. Everything communicated well. Every now and then, I lose communication. I think it’s the Flex because the PanelView Plus displays the tags it should be reading indicating a communication loss and the SLCs instances do not change states. I can ping everything from switch one and two properly. Only way I can get everything to start talking again is to power down the Flex cabinet and bring it back up and my network is back in production. I tied replacing the switch but, no luck. Any ideas?

[Mickey 71]

Can you clarify this. You only need one message instruction, read or write but not both for the same data. So if your Flex is the brains then create a read ( read for each processor) in it and nothing in the SLC's.

[damper 0]

I have one message writing to one SLC, only using two bits out of the word. In the other SLC I have two messages writing and one message reading, I needed two words to for writing and one reading. The Flex contains all message instructions and the SLCs have none. Is it possible that there maybe too much traffic on the network? Edited 16 Nov 2008 by damper

[Mickey 71]

Yes, you should sequence your messages one at a time if your not already doing it.