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Rockwell Automation Publication 1407-UM002B-EN-P - February 2019
Chapter 3
CGCM-DLR Unit Operation
The redundant tracking delay setting adjusts the delay of the tracking function to
prevent the secondary CGCM-DLR unit output from being adjusted into an
undesirable condition. For example, with AVR mode active in the primary
CGCM-DLR unit, if the generator sensing VT fails open the excitation output
goes to a full-on state. Applying a tracking delay reduces the likelihood of this
undesirable operating point to be transferred to the secondary CGCM-DLR unit
when it takes over control.
Watchdog Timer
A watchdog timer time-out is an indication that the CGCM-DLR unit cannot
execute the proper instructions, including those instructions that are required to
energize the fault output. When the Watchdog Timer times out, the
CGCM-DLR unit removes excitation from the system, the CGCM-DLR unit
internal microprocessor is reset, and the output relays (fault and redundancy) are
disabled.