Rockwell Automation 1747-PT1, D1747NP002 Hand-Held Terminal - Manual (Page 235)

Chapter 17
Timer and Counter Instructions
17–3
Timer On–Delay TON Output Instruction
(TON)
(EN)
(DN)
TON
TIMER ON DELAY
Timer
T4:0
Time Base 0.01
Preset 120
Accum 0
F1 F2 F3 F4 F5
ZOOM on TON –(TON)– 2.0.0.0.2
NAME: TIMER ON DELAY
TIMER: T4:0 TIME BASE .01 SEC
PRESET: 120
ACCUM: 0
EN TT DN
0 0 0
EDT_DAT
HHT Ladder Display:
HHT Zoom Display:
Ladder Diagrams and APS Displays:
(online monitor mode)
Operation: The TON instruction begins to count timebase intervals when
rung conditions become true. As long as rung conditions remain true, the
timer adjusts its accumulated value (ACC) each scan until it reaches the
preset value (PRE). The accumulated value is reset when rung conditions go
false, regardless of whether the timer has timed out.
Status Bits
The done bit (DN) is set when the accumulated value is equal to the preset
value. It is reset when rung conditions become false.
The timer timing bit (TT) is set when rung conditions are true and the
accumulated value is less than the preset value. It is reset when the rung
conditions go false or when the done bit is set.
The enable bit (EN) is set when rung conditions are true; it is reset when
rung conditions become false.
Effects of processor mode changes: When the processor changes from the
Run or Test mode to the Program mode or user power is lost while the
instruction is timing but has not reached its preset value, the following
occurs:
•
Timer enable and timing bits remain set.
•
Accumulated value remains the same.
Upon return to the Run or Test mode, the following can happen:
•
If the rung is true, the accumulated value is reset, and the timing and
enable bits remain set.
•
If the rung is false, the accumulated value is reset and the control bits are
reset.
Timer On-Delay (TON)