Emerson Echelon Network issues

[SIPHON]

Currently have a Emerson E2 site fitted with 2 controllers (RX-300 & RX-400) I am faced with a problem where every couple of days I get all the Echelon devices connected CC100 on the RX-400 controller drop off line. I have done the following tests to try to locate the issue. 1. I have tested the ohms resistances between the (+) & (-) legs on the network and I get readings of 120 ohms. 2. Have investigated the Echelon wiring running out to the field the cc100 and have found the last CC100 located on the RX-400 controller loops onto the CC100 located on the RX-300. 3. Have unplugged wiring harness off the CC100 network terminal to try and locate the faulty CC100 that might be dragging down the network or broken wiring. Find nothing, when I re-plug all echelon network cables back into the CC100 they start coming back online. I need further Clarification:- should the Echelon network FROM the RX-300 jump onto the CC100 located on the RX-400 ? should I be getting any resistance from the (-) leg to shield currently reading 22ohms. What's the best way to terminate this configuration http://www.emersonclimate.com/Docume...s/026-1903.pdf page 13. I have been advised that each controller should have its own Echelon network and be terminated individually to the last CC100 online should be terminated and not looped? Attached is the wiring configuration for more detailed information.

[CRANK]

Pretty sure the echelon network should have one network then terminated not go to another e2.

[Coorsman777]

I would say its a termination issue. Systems can communicate perfectly for years without proper termination and then the comm loss will kick in. Then when it is terminated properly it works again.

[SIPHON]

Problem Solved!! Termination & Wiring wasn't setup correctly initially. Separated both echelon networks by removing the crossover loop from the field. Installed a 105 ohms resistor at the end of each echelon network. Was still reading high resistance between shield and (+) leg, split up network and located cut in network wiring, replaced wiring and found network was reading properly 55ohms across (+) & (-) legs and 0 ohms from (+) to shield.

[HVACRsaurus]

Thanks for posting, always good to read about the solution.