Sensaphone SCADA 3000 Users manual - Manual (Page 163)

15-7
Chapter 15: Ladder Logic Programming
Element Function
Number Description Range of Values
0 Timer Enabled 0 or 1 (0=disabled, 1=enabled)
1 Timer Running 0 or 1 (0=disabled, 1=enabled)
2 Timer Done 0 or 1 (0=disabled, 1=enabled)
3 Preset Value 0 to 32,767
4 Timer Value 0 to 32,767
Examples: T,0,0 indicates if Timer 0 is enabled or disabled.
T, 12,4 references the current timer value of timer number 12.
The timer value and status bits can be viewed or changed from the Timer Status form. To
view the timer values, click on the Ladder and C Variables button from the Toolbar on the Main
Programming form. Select the Timers tab. In addition to viewing the state of the timer val-
ues, you can also force changes by double-clicking on the timer value you want to change. A
Change form will appear to let you enter a new value for the timer. Use the Up/Down arrows
to flip through the pages to access the timers you wish to view.
RTO (Retentive Timer)
This instruction is used to turn an output ON or OFF after the timer has been on for a preset
time interval. The specified timer starts at 0 and increments whenever the rung status is true.
It stops when the rung status is false, but it does not reset the TIMER VALUE as in the timer
ON/OFF instructions. The timer can only be reset to zero from the RES(RESET) ladder
instruction having the same address as the timer. The timebase for the RTO instruction is .01
seconds (for example PRESET = 500 is 5 seconds). The timer bits are updated as follows:
ENABLED: Set when rung is true, and reset when rung becomes false.
RUNNING: Set when rung is true and TIMER VALUE is less than PRESET,
and reset when rung is false or when DONE bit is set.
DONE: Set when TIMER VALUE is equal to or greater than PRESET, and reset
when rung is false.
The timer address can only reference one of the 64 internal timers T,0 through T,63. Right-
click on the instruction and choose Select Timer. A list of the 64 timers will be displayed. Select
one and click OK. Set the preset by right-clicking on the instruction and choosing Set Preset.
Enter the preset value and click OK.
The instruction executes in 4.5µs and requires 84 bytes.
The GROUP for this type is the timer number from 0–63. The ELEMENT specifies an indi-
vidual function for the selected timer. There are 5 functions associated with each timer:
Element Function
Number Description
Range of Values
0 Timer Enabled 0 or 1 (0=disabled, 1=enabled)
1 Timer Running 0 or 1 (0=disabled, 1=enabled)
2 Timer Done 0 or 1 (0=disabled, 1=enabled)