Using Basic Instructions
6–7
One-Shot Rising (OSR)
The OSR instruction is a retentive input instruction that triggers an event to occur
one time. Use the OSR instruction when an event must start based on the change of
state of the rung from false to true.
When the 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 conditions preceding it remain true. The
OSR instruction will only become true again if the rung conditions preceding it
transition from false to true.
The controller allows you to use one OSR instruction per output in a rung.
Entering Parameters
The address assigned to the OSR instruction is not the one-shot address referenced
by your program, nor does it indicate the state of the OSR instruction. This address
allows the OSR instruction to remember its previous rung state.
Use a bit address from either the bit or integer data file. The addressed bit is set (1)
for one scan when rung conditions preceding the OSR instruction are true (even if
the OSR instruction becomes false); the bit is reset (0) when rung conditions
preceding the OSR instruction are false.
Note
The bit address you use for this instruction must be unique. Do not use it elsewhere
in the program.
Do not use an input or output address to program the address parameter of the OSR
instruction.
Example Rung
( )
O:3
0
]/[
B3
1
[OSR]
B3
3
( )
O:3
1
] [
B3
2
] [
I:1.0
0
[OSR]
B3
0
Programming
Execution Times
(
µ
sec) when:
True
False
13.02
11.48
[OSR]
efesotomasyon.com - Allen Bradley,Rockwell,plc,servo,drive
