Applications Guide Tracer Graphical Programming - Trane

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Writing the mixed air control program
Figure 166: Economize decision with communicated values
sequence of operation. Modify the first part of the decision to accommodate
the following communicated values:
• Outdoor air temperature
• Economizer enable
The SCC profile contains a variable for the outdoor air temperature, nvi-
OutdoorTemp.However,thereisnosuchvariabletoenableanddisable
theeconomizer.UseaTracerSummitbinaryvariabletosatisfythisneed
(Figure 166).
Network variable input
Tracer
Summit
binary
variable
In Chapter 7, a second stage of decision making was added to accommodate
night heat/cool mode. Figure 167 on page 202 shows how consideration
of pre-cool and warm-up modes changes the second stage of decision
making. Add the Warm-Up and Pre-Cool binary variable blocks and the
logic to consider them in the decision whether to close the outdoor air
damper.
CNT-APG001-EN 201