Falcon Lead Lag Appendix E
E-64
Example:
Before After
Notfiring 3 0
Notfiring 0 0
Firing 2 1
Firing 5 3
Firing 0 4
Firing 4 2
Sequencer Drop Lag boiler selection
When the stager asks the sequencer for a lag boiler to drop the sequencer looks at the StagingOrder numbers of all
Firing boilers. If only one Firing boiler is found, or none are found, then this selection function returns a value that
indicates no boiler may be dropped. Otherwise it returns an identifier for the boiler having the highest StagingOrder
number.
SEQUENCER 1 MINUTE EVENT
Part of the sequencer is called by the timing service at a 1 minute rate to implement lead rotation.
The 1 minute event checks the boiler identified by LeadBoilerSeqNum. If it is Firing then the LeadBoilerRunTime
is incremented.
FORCED LEAD ROTATION:
When the boiler identified by LeadBoilerSeqNum is firing and also LeadBoilerRunTime reaches the Force lead
rotation time parameter time then:
1. The current lead boiler is noted.
2. Lead rotation occurs as described above under Voluntary Lead Rotation (this changes the designation, but
does not change the actual firing status).
SLAVE WRITE: DATA
This allows the slave to accept command messages from a CB Falcon master
SLAVE READ: DATA
This provides the slave status message to be read by a CB Falcon Master. It includes all of the data that is read
from a slave.
SLAVE MODE: USE FIRST, EQUALIZE RUNTIME, USE LAST
• If set to Use First, then this slave will be used prior to using other slaves with other values.
• If this parameter is set to Equalize Runtime, then this slave will be staged according to a run time equalization.
(Any units set to Use First will precede any that are set to Equalize Runtime.)
• If this parameter is set to Use Last, then this slave will be used only after all Use First and Equalize Runtime units
have been brought online.
SLAVE PRIORITY SEQUENCE ORDER: 0-255
Slave sequence order is used to determine the order in which the slaves will be used (staged on) for those with the
same Slave mode setting. Numbers may be skipped, that is 3 will be first if there is no 1 or 2.
NOTE: For Equalize Runtime purposes, 1 does not mean the CB Falcon will be used first every time; that will
vary over time based on the master's run time equalization scheme. In this case the sequence number
determines the relative order in which CB Falcon controls will be used in a round-robin scheme.
If the slave sequence number value is zero, then the slave CB Falcon's ModBus address will be used instead.
If two CB Falcons are set to the same mode and both have the same sequence number then an alert will occur and
the order in which they are used will be arbitrary and is not guaranteed to be repeatable.
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