I have a building that has Summit ver. 11.01. They have a remote building that utilizes 2- FSI D1200 trancievers to convert from the Trane Comm loop(RS485) to fiber optic. I have the same transievers on both ends. On the main building I have an EOL resistor rated at 200 ohms. The remote building has a EOL resistor rated at 1600 ohms. FSI said they recommend a 120 ohm resistor. That takes down all communication when I try the 120 res..
Here is the problem: I can communicate with the other building with the above set up but every 5 minutes to every 60 minutes I get a comm loss from every unit at the remote building. This only last about 10 seconds and they all come back up as comm ok.
Has anyone run into this?
Can I set up a filter in the alarm handler that will ignore the comm loss alarms on these units?
Hard to tell whats going on there. I would suggest having a look with an oscilloscope.
Is this link isolated to the remote - does this link only contain boxes in the remote. We have solved alot of underground comm problems by isolating the link in the BCU- it seems to helps alot. If the link is mixed, do you have room to add another comm4 link in the BCU. If you add a card you pretty easily move the VAVs in the summit programming. In the editor they have a drop down to change the link. I don't believe this will effect the graphics, since they go by the object name. Also you may try to only connect the boxes one at a time and see if you get to a certain number before you have issues.
kwillmech's suggestion about the oscilloscope is a good idea and should help out.
I'll try to gather more info on some more ideas
I believe the transcievers are mixed in with the rest of the controllers. I will investigate adding a comm4 card.
Since this problem is really not giving me any operational problems can I set up a filter to ignore these alarms on these 6 units?
I know that is not the right fix but it could save a lot of money for the customer.
Thanks for you guys input!!!
I don't beleive you can disable foronly those 6. The referencer for alarm routing in the VAV editor doesn't seem to effect the comm notifications. The only option for right not would be to disconnect the link for those VAVs.
You can adjust who gets the alarms in Site Configuration but your probably better off just disconnecting the link for now.