Use Sqo - Allen-Bradley SLC 500 Series Reference Manual
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Also See for SLC 500 Series:
- Manual (270 pages) ,
- Quick start manual (70 pages) ,
- Migration manual (60 pages)
Table of Contents
7-8
Application Specific Instructions
Publication 1747-RM001G-EN-P - November 2008
If you alter a length value with your ladder program,
TIP
make certain that the altered value is valid.
• Position is the word location or step in the sequencer file from/to
which the instruction moves data.
A position value that points past the end of the programmed file causes
a runtime major error to occur.
You may use the reset (RES) instruction to reset a
TIP
sequencer. All control bits (except FD) will be reset to
zero. The Position will also be set to zero. Program
the address of your control register in the RES (for
example,R6:0).
Use SQO
This output instruction steps through the sequencer file whose bits have been
set to control various output devices.
When the rung goes from false-to-true, the instruction increments to the next
step (word) in the sequencer file. Data stored there is transferred through a
mask to the destination address specified in the instruction. Current data is
written to the corresponding destination word every scan that the rung
remains true.
The done bit is set when the last word of the sequencer file is transferred. On
the next false-to-true rung transition, the instruction resets the position to step
one.
If the position is equal to zero at startup, when you switch the processor from
the program mode to the run mode instruction operation depends on whether
the rung is true or false on the first scan.
• If true, the instruction transfers the value in step zero.
• If false, the instruction waits for the first rung transition from
false-to-true and transfers the value in step one.
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