Rockwell Automation Publication 1756-RM006K-EN-P - November 2018 479
Keep the following guidelines in mind when using the Attach to Equipment
Sequence (SATT) instruction.
Guideline Details
Remember that the Logix Designer application
overrides ownership of the Equipment Sequence.
Ownership makes sure that a program can command the
Equipment Sequence, and it locks out any other sequencers.
The Equipment Sequence must be owned by the
program to command it.
Both Equipment Sequences and Equipment Phases must
be owned to be commanded. The ownership commands
are Attach (SATT) and Detach (SDET).
Internal sequencers (programs), external sequencers (FactoryTalk
Batch), and operators use an Attach instruction to command an
Equipment Sequence.
When the sequence is done, relinquish ownership. To relinquish ownership, use a Detach from Equipment Sequence
(SDET) instruction.
Avoid making unnecessary command requests if the
equipment sequence is generating sequence events.
Unnecessary command requests can flood the event processing
buffers and cause you to miss significant events.
Use the Result code to verify ownership, and include
steps that should take place if the attachment fails
because the Equipment Sequence is owned by another
program or by the operator.
Use the Result operand to get a code that shows the success or
failure of the SATT instruction.
On each execution, the SATT instruction tries to take ownership of
the Equipment Sequence. When a program or operator owns an
Equipment Sequence, another execution of the SATT instruction
fails and produces result code 24582. When you use the SATT
instruction, either:
• Limit its execution to a single scan to avoid the 24582 result
code.
• Include the following in your conditions for ownership: result
code = 24582.
See also
Attach to Equipment Sequence on page 465
Result codes for SATT instructions on page 481
Equipment Sequence Instructions on page 465
instructions
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