WattMaster Auto-Zone Plus, Design, Installation And Operation

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Auto-Zone Plus Section 4
Start-Up and Troubleshooting 4-9
1.3.2 Checking the Network Loop at CommLink II
Diagram
The indicated values are typical of a normal system, actual readings may deviate slightly
due to the number of units connected and other system specific factors.
Note:
All of the connected zone managers should be powered up for this test.
Overview
This is a “quick check” to determine if any of the driver chips on the Network loop are
damaged. Since all units will “float” both of their communications connections at about 2.45
Volts, you can quickly check the entire Network loop by unplugging it at the CommLink II.
Note
Be sure that the loop you are testing does not have a short circuit from T to R.
Tip
The Loop LED (located on the front panel) should “flicker” when the CommLink II is
attempting to communicate with the Zone Managers. There is a noticeable change in
the flicker when the loop is disconnected, if you observe a normal functioning unit.
When the loop is reconnected it may take up to 60 seconds before the CommLink II
re-establishes communications with the Zone Managers.
Measurements
Network Loop Acceptable Range
T - G (SHLD) 2.4-to-2.5 Volts DC
R - G (SHLD) 2.4-to-2.5 Volts DC
Action
Condition Action
If voltages are too high or too low on either
side One or more of the Zone Manager
MiniLinks has a damaged Network driver
chip. Disconnect Zone Managers one at a
time to isolate the problem.
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