Does he not want to use what is there, does he want to use a uniform temp or do they not have actual OA for all the units?
Have a customer with a few sites that each have appx. 20 Carriers with RTU-Open controllers. The units, as is, use their individual OA sensor for various control strategy's. What customer would like is to have 1 unit sending its OA temp to the others. In looking through the unit info it appears the OA is read only. Anyone know if what they want is doable.
Does he not want to use what is there, does he want to use a uniform temp or do they not have actual OA for all the units?
Each unit now has its own OA sensor. What they want is a uniform OA temp which will be the same for all units. If I pick 1 unit to broadcast its OA temp then done deal, but where I could do that on a CCN network I am unsure if same goes with the RTU-Open, or for that matter how to make it work.
Yes you can hard wire one OA sensor to one rtu open and make the others look at. You will to go to properties/ network points found the OA sensor. Right click on it and global modify. It find all the rtu opens on the network and point them to the hard wired controller. The OA temp does not show up on the default rtu graphic , but could always added it with view builder. Hope this makes sense
With CCN you broadcast, with Open you will need to read. Open will broadcast when a Linkage is setup.
You want System Outdoor Air Temperature, which is found under Properties\Network Points. Click the Name, then Details. From there expand to the unit with your OA Sensor. On unit with the master OAT, go to Properties\BacNet Points and make sure the OAT is Network Visible.
As I have never done this when a unit that has a local hardwired sensor, you may need to disconnect the hardwired sensor. The programming will automatically use the System Outdoor Air Temperature when there is no hardwired sensor.
There is no programming parameter to make the unit use the System OAT versus the local hardwired sensor that I have found. If you look at Outdoor Air Temperature Source (oat_status) in BacNet Points it will identify which sensor the programming is using. Values are Local/N-A/Locked Value/Linakge/Network.
hope this helps ..... Let us know how this works out .....
Originally Posted by Qui-Gon Jinn (Star Wars Episode 1)