Falcon Lead Lag Appendix E
E-48
Slave Status Manager
The LL master keeps track of slave status for each unit that is enabled as a slave device. The slave status manager
operates internally for each slave device (up to 8).
There is a table entry for each device containing the following data:
• SlaveState:
— Unknown - indicates the table entry is unused and empty
— Available - indicates the slave is OK and ready to use, but is not
— currently firing as a slave
— AddStage - stage is getting ready to fire
— SuspendStage - stage was getting ready but is not needed
— Firing - indicates the slave is currently firing
— OnLeave - indicates the slave is operating for some other demand source within it that has higher priority than
slave demand.
— Disabled - indicates the slave is locked out or disabled in some way
— Recovering - indicates the slave is in a time delay to ensure that it is
OK before it is again considered to be available.
• RecoveryTime: Saves how long the slave must be OK to recover.
• RecoveryTimer: Used to measure the slaves recovery time
• RecoveryLimitTimer: Enforces a maximum slave recovery time
• DataPollFaultCounter: Used to tolerate momentary communication problems and to act on these if they are
excessive.
• StatusReadFaultCounter: Used to tolerate momentary communication problems and to act on these if they are
excessive.
• AbnormalFaultCounter: Used to tolerate momentary abnormality
• StagingOrder: Used to record the stage-on order, for use by the sequencer when it needs to drop a stage.
• Storage for each item described in the Periodic data polling section
• Storage for each item described in the Slave status read response section
• Slave Command - the command word from the master to the slave.
Features common to all states
• Whenever a slave device is not in an expected condition then a recovery function is used to set up timers to give a
faulty slave:
— minimum time that it must appear to be OK, and
— limit how long a slave has to recover from any error.
• If the slave status read was bad then the slave's FaultCounter is incremented and if it to reaches the fault value
tries, then a recovery action is invoked.
This action does nothing else if the status read was Bad.
If the slave status read was OK then the status function puts the slave read response data in a slave status table.
If a transition to another state is indicated then the SlaveState is simply set to the indicated state.
Data poll response handling
VALID RESPONSE MESSAGE
When a slave responds with a properly formatted message it is examined to see if Slave enable value is "Enable
for Master".
• If the "Enable for Master" value is not present then the slave status table is checked and if the slave is not in the
table then the message is ignored (this is normal). However if the slave is in the table then the message is stored
as usual and the slave will invoke the action as a disabled slave and cause recovery action to occur.
• If the "Enable for Master" value is present then the slave status table is checked and
if the slave is not in the
table then the slave data is stored in an empty position in the table. However
if the slave is in the table then the
message is stored as usual (this is the normal case).
INVALID RESPONSE OR NO RESPONSE
When a CB Falcon responds to a data poll with an improperly formatted message or it does not respond then the
slave status table is checked and:
If the polled slave device is in the table then the Data Poll Fault is noted. If this causes a fault counter to exceed the
fault value then the SetRecovering handling is invoked.
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