Sensaphone SCADA 3000 Users manual - Manual (Page 161)

15-5
Chapter 15: Ladder Logic Programming
OSR (One-Shot Rising)
This instruction is used to make an event occur one time. It is not associated with a particular
input but rather with the instructions preceding it on the rung itself. When rung conditions
preceding the OSR instruction go from false-to-true, the OSR instruction will be true for one
scan. After one scan is complete, the OSR instruction becomes false, even if the rung condi-
tions preceding it remain true. The OSR instruction will only become true again if the rung
conditions preceding it transition from false-to-true again.
The OSR address identifies the location where the OSR bit is stored. The OSR bit is used to
remember the previous rung state. The bit address you use for this instruction must be unique.
The instruction executes in 3.5µs and requires 44 bytes.
Following is a list of the data points that may be used with OSR instructions:
Ladder bits
Note: You can only use one OSR instruction per rung, and you cannot use the
OSR instruction in a branch.
TON (Timer On-Delay)
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 begins running when the rung status changes
from false to true. It then keeps running, incrementing the TIMER VALUE, as long as the
rung remains true, until it reaches the PRESET value. If the rung becomes false, then the
timer stops and resets to 0. The timebase for the TON instruction is .01 seconds (for example
PRESET = 500 is 5 seconds). You can have up to 64 timers. The timer bits are updated as fol-
lows:
ENABLED: Set when rung is true, and reset when rung is 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: