WattMaster Auto-Zone CV, Design, Installation And Operation

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Auto-Zone CV & CV-EX
Section 4
Start-Up and Troubleshooting 4-19
Communications Loops
Checking CommLink Local Loop – CV
Diagram
Overview
This test checks for proper loop voltages at the CommLink II.
Tip
The Loop LED (located on the front panel) should “flicker” when the CommLink II is
attempting to communicate. The Loop LED will flicker more noticeably for a few sec-
onds when first powered up. If the Loop LED does not flicker, the unit is defective.
Proper loop voltages are essential for reliable communications. It is normal to see fluctua-
tions at this point on the CommLink II. The average value should be close to the acceptable
range described below.
Values will vary upon initial powerup for about 10-15 seconds as
the unit attempts to communicate.
Measurements
Network Loop Acceptable Range
T - G (SHLD) 2.9 - 3.1 Volts DC
R - G (SHLD) 1.9 - 2.1 Volts DC
Action
Condition Action
If voltages are too high or too low on either
side 1. Unplug the Comm loop from the
CommLink II and Check for proper
loop voltages. If a problem exists, dis-
connect each CV Unit from the loop
until the problem is isolated.
2. Check the CommLink II Driver chip.
Replace the driver chip if necessary
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