Termination Resistor Placement For Comm5 Links - Trane Tracker Version 12 Hardware Installation

Chapter 3 Termination board wiring
34

Termination resistor placement for Comm5 links

Install one 105 Ω resistor across the communication link terminals of the
device at the beginning of the daisy chain, which is typically a Tracker
controller. Then install a second 105 Ω resistor across the communication
terminals at the last UCM on each link. See Figure 17 on page 35 for an
example of a link that begins with a Tracker controller. See Figure 18 on
page 36 for an example of a link that does not begin with a Tracker
controller.
Note:
If, after installation, the link is extended to add more UCMs,
the resistor must be relocated to the new last UCM on the link.
IMPORTANT
For maximum performance of the Comm5 link, use the 105 Ω resistors
that are included with the Tracker controller. If they are not available, as
a second choice, use a 100 Ω, ¼ W, 5% tolerance resistor, or as a third
choice, a 110 Ω, ¼ W, 5% tolerance resistor. Failure to comply may cause
the controller to malfunction.
The resistor value can be determined by reading its color bands. Table 9
provide the resistor color coding.
Table 9. Resistor color band table
Tolerance
Ω
105 ± 1% tolerance
Ω
100 ± 5% tolerance
Ω
110 ± 5% tolerance
If a repeater is used, each link of the configuration that is created by the
repeater requires termination resistors (see "Requirements for repeaters
on Comm5 communication links" on page 37).
Create a set of as-built drawings or a map of the communication wire
layout during installation. Ensure that sketches of the communication
layout show the placement of the termination resistors.
Color sequence
Brown, black, green, brown
Brown, black, brown, gold
Brown, brown, brown, gold
BMTK-SVN01D-EN
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