Tof - Timer, Off-Delay - Allen-Bradley MicroLogix 1100 Instruction Set Reference Manual

efesotomasyon.com - Allen Bradley,Rockwell,plc,servo,drive
172 Timer and Counter Instructions

TOF - Timer, Off-Delay

TOF TOF
Timer Off Delay
Timer T4:0
Time Base 1.0
Preset 0<
Accum 0<
Timer Control and Status Bits, Timer Word 0 (Data File 4 is configured as a timer file for this example.)
Bit
bit 13 - T4:0/DN DN - timer done
bit 14 - T4:0/TT TT - timer timing
bit15 - T4:0/EN EN - timer enable rung conditions are true
Publication 1763-RM001C-EN-P - October 2009
Instruction Type: output
EN
Execution Time for the TOF Instructions
DN
Controller When Rung Is:
True
2.68 μs
MicroLogix 1100
Use the TOF instruction to delay turning off an output. The TOF
instruction begins to count time base intervals when rung conditions
become false. As long as rung conditions remain false, the timer
increments its accumulator until the preset value is reached.
The accumulator is reset (0) when rung conditions go true, regardless of
whether the timer is timed out. TOF timers are reset on power cycles and
mode changes.
Timer instructions use the following control and status bits:
Is Set When:
rung conditions are true
rung conditions are false and accumulated value
is less than the preset value
ATTENTION
False
2.68 (DN=1), 4.03
(DN=0) μs
And Remains Set Until One of the
Following Occurs:
rung conditions go false and the accumulated
value is greater than or equal to the preset
value
rung conditions go true or when the done bit is
reset
rung conditions go false
Because the RES instruction resets the accumulated value
and status bits, do not use the RES instruction to reset a
timer address used in a TOF instruction. If the TOF
accumulated value and status bits are reset,
unpredictable machine operation may occur.