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Place Trane Communicating Thermostats on a separate link.
Trane Communicating Thermostats (TCTs) may have communication issues when mixed on a link with
Trane UC devices that use the 76,800 baud rate. To prevent this, place all TCTs on a separate link with
a baud rate of 76,800.
If the TCTs cannot be isolated on a separate link, reduce the baud rate of all devices on the mixed network
to 38,400 baud to eliminate this issue. Although the slower baud rate will affect the bandwidth, in most
cases the slower rate will have no significant effect on performance. Data intensive operations such as
harvesting trend logs will experience some slower performance.
Note: The Tracer
Custom Programming
Limit Tracer
Very few supervisory control routines require calculations or updates more frequently than once per
minute - and often can be run at a much slower rate (such as every 5, 10 or 15 minutes). Tracer
TGP2 routines that read values from controllers on BACnet
requests and impact performance. Therefore, if it is possible to accomplish the required control function
without reading data directly from unit controllers, it will improve overall performance. (See below for
suggestions.) If it is necessary to read data from unit controllers in TGP2, choose the slowest possible run
frequency to optimize performance.
Use event triggered TGP2 to reduce run frequency.
Use Tracer
Tracer
their controller members. These calculated values are available to TGP2 as "properties" of the TGP2
Applications Blocks. Using the already calculated values will avoid additional unnecessary link loading.
For example, Area performs group calculations for min, max, and average space temperatures. VAS also
has a number of group calculations for all of its member VAV controllers.
Custom Graphics
Limit number of points displayed on a Tracer
Custom graphics with many point values from unit controllers on a BACnet
load and present the data on the screen. Use these data points wisely. If a graphic is loading slower than
desired, consider reducing the number of data points, or use multiple graphics to distribute the data points.
For example, instead of a single floor plan graphic with 40 space temperature values, two floor plans (east
wing and west wing) each with 20 space temperatures will give better performance. In any case, Trane
recommends an upper limit of 90 data points.
BAS-SVX51L-EN
®
SC+ has a default baud rate at 76,800 baud. If using TCTs, the Tracer
MS/TP devices on the same physical MS/TP link must be set to the 38,400 baud rate.
®
SC+ TGP2 run frequency.
®
SC+ System Applications for common calculations.
®
SC+ System Applications (Area, VAS, Chiller Plant Control) perform calculations using data from
®
MS/TP links will load the MS/TP link with their
®
SC+ Custom Graphic.
®
MS/TP link will take time to
Best Practices
®
SC+ and all
®
SC+
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