Rockwell Automation 1402-LSM Line Synchronization Module Installation Instructions - Manual (Page 26)

Chapter 3
General Operation
3–4
Demand Period
This entry is used to specify the desired period for demand measurement.
The value is specified in minutes and must be between 1 and 99.
Number Of Demand Periods
This entry specifies the number of demand periods that should be
averaged to determine the actual demand. The value must be between 1
and 15.
Synchronization
The functionality of the synchronization process is based on the
synchronization discrete outputs from the PLC–5 received via the PLC
backplane. The “Initiate Synchronization” output from the PLC–5 begins the
synchronization process when it is asserted. It must remain asserted during the
entire process. If the initiate signal is removed, the synchronization process is
terminated. In addition to the initiate signal, one of the
“Auto–Synchronization”, “Check Synchronization”, or the “Permissive
Synchronization” discrete outputs from the PLC–5 must be asserted. If more
than one of those signals is present, the synchronization fails and the
“Synchronization Failure” discrete input to the PLC–5 will be asserted.
Additional information pertaining to the cause of the failure may be obtained
by reading the appropriate block transfer data from the “Synchronizing Bus
Error Parameters” table. (See Appendix B, “Block Transfer and Discrete I/O
Definition”, for additional information.) If new setup information is received
via block transfer while the LSM is in the Synchronization mode,
synchronization is terminated. The new configuration data is evaluated and
normal operation is resumed upon acceptance of the data.
The “Auto–Synchronization” discrete output from the PLC–5 causes the
LSM to issue the appropriate error signals, both continuous discrete inputs
and via block transfer, to cause, via the PLC–5, the synchronizing bus
voltage, frequency, and phase to align with the reference bus. Once these
conditions are satisfied, the “Close Breaker” discrete input to the PLC–5 is
asserted based on the synchronization configuration. In the event a “dead
reference bus” condition exists, the “Synchronization Failure” discrete input
to the PLC–5 is asserted. Additional information pertaining to the cause of
the failure may be obtained by reading the appropriate block transfer data
from the “Synchronizing Bus Error Parameters” table. (See Appendix B,
“Block Transfer and Discrete I/O Definition”, for additional information.)
The “Check Synchronization” discrete output from the PLC–5 causes the
LSM to function in the same manner as the “Auto–Synchronization” discrete
output from the PLC–5 except it will not assert the “Close Breaker” discrete
input to the PLC–5. This mode is useful for testing the system.
Operational Characteristics
Continued