Output Statements: Hold Vs Track - Simplex 4100ES-S1 Programming Manual

Document: LT0400
9.3.4

Output Statements: HOLD vs TRACK

The two commonly used output opcodes are HOLD and TRACK. The main difference is
that a HOLD command is evaluated only when the inputs side of the equation goes True (on
the transition from false to true).
TRACK is evaluated when the inputs side is True and again when the inputs side goes
False. The evaluation occurs only when the change on the inputs side changes state – it is
not evaluated again until the inputs side changes state.
When combined with the ON and OFF commands, all possible control requirements can be
met:
HOLD ON – when the inputs side goes True, the output turns on.
HOLD OFF - when the inputs side goes True, the output turns off.
TRACK ON – when the inputs side goes True, the output turns on and when the inputs
side goes False, the output turns off.
TRACK OFF – when the inputs side goes True, the output turns off and when the inputs
side goes False, the output turns on. When rebooted or after power up, the output will be
turned on and remain on until the inputs side is True.
4100ES-S1 Programming Guide
9-7
Custom Control