Trane Tracer MP503 - 0-20 mA inputs; 0-10 Vdc inputs; Outputs

18 CNT-SVX09E-EN
Network Variable Bindings
of the SNVT that matches the variable selected in the MP503. Table 4 shows the bindings required
between the MP503 and MP581 #2.
Table 4. Bindings for example 2
After completing the bindings, program Tracer MP581 #2 to calculate enthalpy from the outside air
temperature and humidity.\
Important:

Custom programming is required to display this data on the operator display of
Tracer MP581 #2. Remember that the outside air humidity is being transmitted over
the network in units of mA. Some custom programming is required in Tracer MP581
#2 to convert the humidity from units of mA to units of percent (%) before performing
the enthalpy calculation.
Example 3: Control a Binary Output on the MP503 from a MP581
This example shows an nvi on the MP503 being bound, which allows a binary output on the MP503
to be controlled by another device on the LonTalk network. In this example, binary output 1 on the
MP503 is starting and stopping an exhaust fan. The MP503 is communicating via the LonTalk
network to a MP581 that is controlling an AHU. The AHU and the exhaust fan follow the same
schedule; for example, whenever the AHU runs, the exhaust fan runs.
Bind an nvo on the MP581 to an nvi on the MP503 so the AHU and exhaust fan run together. Figure 8
sh
ows the Lo
nTalk network for this example.
Figure 8. LonTalk network for example 3
®
LonTalk link
Tracer MP503
Tracer MP581 with
operator display
Additional
LonTalk
devices
Network Variable Output on the
MP503
Binding To
Network Variable Input on the
MP581 #2
nvoTemperature1 
nviTemp01
(a)
(a) The MP581 has 40 generic temperature (SNVT_temp_p) network variable inputs available for binding (nviTemp01 through
nviTemp40).
nvoCurrent2 
nviCurrent_mA01
(b)
(b)The MP581 has 40 generic temperature (SNVT_temp_p) network variable inputs available for binding (nviTemp01 through
nviTemp40).
1
The Tracer MP581 has 40 generic temperature (SNVT_temp_p) network variable inputs available for
binding (nviTemp01 through nviTemp40).
2
The Tracer MP581 has 8 generic current (SNVT_amp_mil) network variable inputs available for binding
(nviCurrent_mA01 through nviCurrent_mA08).