First of all let me wish you the best for this new year that´s starting.

Maybe you could help me with an issue.

The issue is that i have 3 30RB Chillers who are going out of communication with not only the CVIEW but also with the bus. Let me explain.

First we have all the elements on 0 bus but after we saw that the elements where crashing data, we split that bus in 3 secondary buses with Ethernet converters.

After the changes the comm between this Chillers and the rest of the elements was ok, we could check that cause the 6400 that controls the bombs has some network points from the chillers that worked ok and went to “comm failure” when the chiller was off or we disconnect the bus from the chiller. Also when we used the “search” tool it finded the 3 of them without problems (we isolate that part of the bus to take the traffic to the minimum).

Now, after we made a number 1 bus in wich there are the 3 chillers, the 6400 with 3 I/O´s, 1 CSM, 13 VAV´s, 6 AHU´s and the 23 modbus translators and we changed the bus speed of all of the CCN elements to 38.4K the communication is a lot better but the 3 chillers jumps off of the bus periodically.

If we go and connect directly to the CCN terminals of any of the 3 chillers, the search tool didn´t find any of them neither the CVIEW , only after we turn off and on the chiller (reset) it begins to communicate (with CVIEW also) but only for a short period of time cause after 24 hours more or less (we have not the exact amount of time) it jumps off the bus again and never comes back. That’s the way we know its not a bus traffic problem but a internal problem with the chillers.

This 3 chillers where ordered with a modbus translator inside of them that we are not using cause there´s no modbus bus to the chillers. The funny thing is that the chillers goes off of communication but the modbus cards stay´s inside the bus even when theyre inside the chillers.

Any idea why this is happening to the chillers? we think that maybe is cause we changed the speed from 9.6 to 38.4. but honestly we are clueless.

I apreciate any help that you could gave me cause this is the last thing we have to do to finish this job.

Best regards and thanks