Siemens Simatic S7 Series Manual page 53

S7-200 SIMATIC Timers.
SIMATIC On-Delay Timer
(TON)
The.S7-200.SIMATIC.LAD.instruction.set.includes.three.types.
of.timers:.On-Delay.Timer.(TON),.Retentive.On-Delay.Timer.
(TONR),.and.Off-Delay.Timer.(TOF)..Timers.are.represented.in.an.
S7-PLC.ladder.logic.program.by.boxes.
S7-200.timers.have.a.resolution.of..millisecond,.
0.milliseconds,.or.00.milliseconds..This.resolution.appears.
in.the.lower.right.corner.of.the.timer.box..As.shown.in.the.
following.illustration,.the.resolution.and.type.of.timer.that.can.
be.used.depends.on.the.timer.number..The.maximum.value.of.
time.shown.is.for.a.single.timer..By.adding.program.elements,.
greater.time.intervals.can.be.timed.
Timer Number (T0 to T255)
Txxx
IN TON
PT xxx ms
On-Delay Timer
1 ms, 10 ms, or 100 ms
Timer Type
TONR
(retentive)
TON, TOF
(non-retentive) T33 to T36, T97 to T100
T37 to T63, T101 to T255
The.previous.example.illustrated.how.a.hardware.on-delay.timer.
works..The.corresponding.software.function.in.the.S7-200.
SIMATIC.LAD.instruction.set.is.the.On-Delay Timer (TON)..
After.the.On-Delay.Timer.(TON).receives.an.enable.(logic.).at.
its.input.(IN),.a.predetermined.amount.of.time.(preset.time.-.PT).
passes.before.the.timer.bit.(T-bit).turns.on..The.T-bit.is.a.logic.
function.internal.to.the.timer.and.is.not.shown.on.the.symbol..
The.timer.resets.the.accumulated.time.to.zero.when.the.
enabling.input.goes.to.a.logic.0.
52
SIMATIC Timers
Txxx
IN TONR
PT xxx ms
Retentive On-Delay Timer
Timer Resolution
Timer Number Resolution
T0, T64
T1 to T4, T65 to T68
T5 to T31, T69 to T95
T32, T96
Txxx
IN TOF
PT xxx ms
Off-Delay Timer
Maximum Value
1 ms 32.767 seconds
10 ms 327.67 seconds
100 ms 3276.7 seconds
1 ms 32.767 seconds
10 ms 327.67 seconds
100 ms 3276.7 seconds