WattMaster WCC II - Manual (Page 237)

Section 5: Installation Guide
WCC II Operator’s Guide
Operator Interfaces 5-35
CPU to SAT II-B Wiring
Use low capacitance, 18 gauge twisted pair, shielded
for lengths up to 2000 feet from the CPU to the farthest
satellite.
Ground the shield at the CPU (personal computer)
chassis only (do not ground the shield at each SAT II-B).
It may be necessary to install a terminating resistor
between the “R/T” and “C” terminals on the farthest
satellite from the CPU (front end personal computer) if
intermittent communication is present. The terminating
resistor is more apt to be required on jobs that have a lot
of communication wire and/or the communication wire
capacitance is relatively high. A resistance value of 5 to
20 ohms is used. Generally, start with a 10 ohm resistor.
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