Carrier RTU OPEN 11-808-427-01 - Manual (Page 81)

RTU Open 75
Single Point Linkage
The RTU Open receives data from other Open controllers when they are installed as part of an Open system.
The data transfer may take the form of Single Point Linkage (SPL), which is automatic, or Device Address
Binding, which you must configure.
Currently, the RTU Open implements Single Point Linkage for 3 variables: Refer to configuration section -
complete list - make list to system system configuration1.....might be different for RTU - might be unit config
•
System Cool Demand Level
• System Heat Demand Level
• System Outside Air Temperature
Network Points for which SPL has been implemented are displayed in the i-Vu application and Field Assistant
on the Properties page > Network Points tab.
The following example involves outside air temperature. System Heat & Cool Demand Level behaves
similarly, except that their usage involves a specific application loaded on a Universal Controller Open. See UC
Open Installation Guide for additional information. In either case, note that the BACnet type and instance
numbers specified in the Address field of these variables have been predefined.
Network variables for which SPL is used are easily identified on the Properties page > Network Points tab.
The asterisk in the BACnet address invokes the SPL function. These addresses cause the controller to issue a
BACnet “who has” command for this variable. The controller binds to the closest of the first five devices from
which it receives a valid response.
Appendix B: Single Point Linkage and Device Address Binding