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S5 AWL Command: SA (Off-Delay Timer)

S5 AWL instruction SA (Off-Delay): Output stays TRUE for the set duration after input goes FALSE. Direct equivalent to IEC TOF.

·4 min read
S5AWLSAtimeroff-delayTOFAusschaltverzögerung

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S5 AWL Command: SA (Off-Delay Timer)

SA starts an off-delay timer. The output goes TRUE immediately when the input (VKE) goes TRUE. When the input goes FALSE, the timer starts counting. The output stays TRUE for the programmed duration after the input went FALSE.

Syntax

L  KT xxx.y
SA T n

S7 Equivalent

S5 AWLS7 FunctionIEC 61131-3
SAS_OFFDTTOF (Off-Delay Timer) — 1:1 match

SA → TOF is a direct equivalent, like SD → TON.

Timing Diagram

E 0.0:  ____/‾‾‾‾‾‾‾‾\________________
T 5:    ____/‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾\________
                       |--5s--|

Code Example

U   E 0.0
L   KT 050.1       // 5 seconds
SA  T 5

U   T 5
=   A 4.0           // Stays ON for 5 seconds after E 0.0 goes FALSE

Typical Use

Cooling fan run-on after motor stops, lubrication pump after-run, light delay-off in stairwells, process flushing after cycle end.

All Five S5 Timer Types Summary

TimerNameInput TRUEInput FALSE before timeIEC Equivalent
SIPulseOutput TRUEOutput FALSE immediatelyTP (approx.)
SEExtended PulseOutput TRUEOutput stays TRUETP (approx.)
SDOn-DelayTimer countsTimer resetsTON (exact)
SSRetentive On-DelayTimer countsTimer continuesNo direct IEC
SAOff-DelayOutput TRUETimer counts, output stays TRUETOF (exact)

Part of the S5 AWL Command Reference. Maintained by PLCcheck.ai.


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