Rockwell Automation 1772-LS_LSP,D17726.8.6 PROG/OPER MANUAL-MINI PLC-2/05 - Manual (Page 69)

Timers and Counters
Chapter 8
8Ć2
Two bits in the accumulated value word are status bits:
Bit 15 is the timed bit. It is either set or reset when the timer has timed out.
The setting or resetting depends on the type of timer instruction used.
Bit 17 is the enable bit. It is set when rung conditions are true and is reset
when rung conditions are false.
There are four types of timer instructions available with the controller:
timer on-delay
timer off-delay
retentive timer on-delay
retentive timer reset
We will look at these timers in detail.
Timer On/Timer Off Delay
Purpose: The Timer On and Timer Off Delay instructions can be used to turn a
device on or off once an interval is timed out.
Timer On Delay
The Timer On Delay instruction is programmed as an output instruction.
010
00
TON
030
1.0
PR 150
AC 000
When the timer on delay rung condition becomes:
True
Timer cycle begins.
Timer increments its AC value.
Bit 15 is set when AC=PR and the timer stops timing.
Bit 17 is set.
False
Accumulated value resets to 000.
Bits 15 and 17 are reset.