Specifications

SIMATIC Instructions
9-15
S7-200 Programmable Controller System Manual
C79000-G7076-C233-01
9.3 SIMATIC Timer Instructions
On-Delay Timer, Retentive On-Delay Timer, Off-Delay Timer
The On-Delay Timer and Retentive On-Delay Timer
instructions count time when the enabling input is ON.
When the current value (Txxx) is greater than or equal to
the preset time (PT), the timer bit is ON.
The On-Delay timer current value is cleared when the
enabling input is OFF, while the current value of the
Retentive On-Delay Timer is maintained when the input
is OFF. You can use the Retentive On-Delay Timer to
accumulate time for multiple periods of the input ON. A
Reset instruction (R) is used to clear the current value of
the Retentive On-Delay Timer.
Both the On-Delay Timer and the Retentive On-Delay
Timers continue counting after the Preset is reached, and
they stop counting at the maximum value of 32767.
The Off-Delay Timer is used to delay turning an output
OFF for a fixed period of time after the input turns OFF.
When the enabling input turns ON, the timer bit turns ON
immediately, and the current value is set to 0. When the
input turns OFF, the timer counts until the elapsed time
reaches the preset time. When the preset is reached, the
timer bit turns OFF and the current value stops counting.
If the input is OFF for a time shorter than the preset
value, the timer bit remains ON. The TOF instruction
must see an ON to OFF transition to begin counting.
If the TOF timer is inside an SCR region and the SCR
region is inactive, then the current value is set to 0, the
timer bit is turned OFF, and the current value does not
count.
Inputs/Outputs Operands Data Types
IN (LAD) Power Flow BOOL
IN (FBD) I, Q, M, SM, T, C, V, S, L, Power Flow BOOL
PT VW, IW, QW, MW, SW, SMW, LW, AIW, T, C, AC, Constant, *VD,
*AC, *LD
INT
L
A
D
S
T
L
TON Txxx, PT
TONR Txxx, PT
TON
IN
PT
Txxx
TONR
IN
PT
Txxx
F
B
D
Txxx
PT
TOF
IN
TOF Txxx, PT
222 224
333
221