CNT-SVX09E-EN
17
Network Variable Bindings
and then select the MP581. The Rover service tool shows only the variables in the MP581 for the
SNVT that matches the variable selected in the MP503 (refer to
.
Table 3.
Bindings for example 1
After completing the bindings, program the MP581 to display this data on the operator display.
Important:
Remember that the outside air humidity is being transmitted over the network in
units of mA. Some custom programming is required in the MP581 to convert the
humidity from units of mA to units of percent (%). Custom programming in the
MP581 also uses the outside air temperature and humidity to calculate the outside
air enthalpy and use it to control the economizer of the AHU.
Example 2: Display Sensor Readings from a MP503 on Two Different MP581 Operator
Displays
This example builds on example 1 and shows that bindings can be
one-to-many.
In this example,
a second MP581 is added to the system as described in example 1. The second MP581 also controls
an AHU. This AHU requires the outside air enthalpy in order to control its economizer. As in
example 1, use bindings to allow the economizer control in the second MP581 to calculate outside
air enthalpy.
shows the LonTalk network for this example.
Figure 7.
LonTalk network for example 2
®
LonTalk link
Tracer MP503
Tracer MP581 #1
with operator display
Tracer MP581 #2
with operator display
Additional
LonTalk
devices
Use the Rover service tool to create bindings. (Refer to the
Rover Operation and Programming
Guide
(EMTX-SVX01). Using the Rover service tool, select the network variable from the MP503
and then select the second MP581. The Rover service tool shows only the variables in MP581 #2
Network Variable Output on the
MP503
Binding To
Network Variable Input on the
MP581
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 8 generic current (SNVT_amp_mil) network variable inputs available for binding (nviCurrent_mA01 through
nviCurrent_mA08).
nvoBIP3Status
nviSwitch01
(c)
(c) The MP581 has 40 generic binary (SNVT_switch) network variable inputs available for binding (nviSwitch01 through nviS-
witch40).
nvoBIP4Status
nviSwitch01
