Trane TRACER SUMMIT BAS-APG001-EN Manuel D’Utilisation

Page de 156
BAS-APG001-EN
121
Chapter 8
Network variable bindings
Overview
The LonTalk communications protocol allows data to be shared between 
devices (stand-alone or with a BAS) on a LonTalk network. This is called 
peer-to-peer communication. As an example of peer-to-peer communica-
tion, two or more devices serving the same space share data, such as a 
temperature reading, without having to pass the data through a BAS.
Network variables are used to share data between devices. The method 
used to direct data from one device to another is called network variable 
binding, or just binding. A network variable output from one device is 
bound to a network variable input on another device. An output variable 
from one device can be bound to input variables on many other devices. 
Binding network variables
Each network variable is a standard type. This standard type is referred 
to as a standard network variable type (SNVT). To bind two variables 
together they must be the same SNVT. For example, an output of type 
SNVT_temp_p can only be bound to an input of type SNVT_temp_p. For 
more information about SNVTs, see the LonMark™ Web site (www.lon-
mark.org). From that Web site you can download the official list of 
SNVTs.
IMPORTANT
Only LonTalk devices can use network variable binding. Devices on 
other communications links do not have this capability.
BAS communications typically do not require the use of network variable 
binding because a Tracer Summit BCU will automatically bind to the 
proper data in a device. However, communications speed may be 
increased between two devices by binding their data rather than having 
the BAS read the information from one device and then broadcast it to 
another. 
Use the Rover service tool to create bindings. (See the Rover Operation 
and Programming
 guide, EMTX-SVX01E-EN.)