Equipment Sequence Assign Sequence Identifier (SASI)

This instruction applies to the
Logix Designer
5580 P-controllers. The
Logix Designer
5580 P-controllers also support controller redundancy.
TIP:
When using this instruction with
ControlLogix
redundancy system, outputs controlled by this instruction may not be bumpless during redundancy switchover, if the instruction and sequence program are not scheduled in the highest priority task.
WARNING:
When using redundancy with an
Equipment Sequence
, sequence execution may not be as expected after switchover if the phase and sequence are not scheduled on the same task.
Use the Assign Sequence Identifier (SASI) instruction to assign a sequence ID to the
Equipment Sequence
. You can only set the sequence ID when these prerequisites are met:
  • The controller is online.
  • The
    Equipment Sequence
    is in the IDLE state.
  • You have taken ownership of the
    Equipment Sequence
    , or there is no other owner of the
    Equipment Sequence
    .
The sequence ID can be up to 82 characters in length, using these printable ASCII characters:
a-z, A-Z, 0-9, !"#$%&'()*+,-./:;<=>?@[\] ^_`{|}~ and space
This is a transitional instruction. Follow these steps when using it:
  • In ladder logic, insert an instruction to toggle the rung-condition-in from false to true each time the instruction should execute.
  • In a Structured Text routine, insert a condition for the instruction to cause it to execute only on a transition.
When a tag is assigned to store the result of an SASI instruction, the instruction returns a result code when it runs. Result code 0 indicates that the SASI instruction ran successfully. The other codes indicate that the instruction did not run successfully and provide additional information about the reason for the instruction failure.
Available Languages
Ladder Diagram
SASI_LD_avail_v34
Function Block Diagram
This instruction is not available in Function Block.
Structured Text
SASI(Sequence Name, Sequence Id, Result)
Operands
Ladder Diagram
Operand
Data Type
Format
Description
Sequence Name
SEQUENCE
name of the
Equipment Sequence
Equipment Sequence
to which you want to assign an identifier.
Sequence Id
STRING
Tag
Enter a STRING tag in which the identifier is stored, or a quoted string containing up to 82 characters.
Result
DINT
Tag
For an instruction to return a success or failure code, enter a DINT tag where the result code is to be stored. Otherwise, enter 0.
Structured Text
The operands are the same as for the Ladder Diagram.
SASI Result Codes
Code (Dec)
Description
0
the Sequence Id was successfully assigned.
24578
The Sequence state is not IDLE or there presently is a Sequence failure.
24579
Sequence is attached by another owner.
Affects Math Status Flags
No
Major/Minor Faults
None specific to this instruction. See Index Through Arrays[1] for operand related faults.
Execution
At instruction execution, the SASI instruction attempts to assign a string identifier to the specified
Equipment Sequence
.
Ladder Diagram
Condition
Action Taken
Prescan
No action taken
Rung-condition-in is false
No action taken
Rung-condition-in is true
The instruction executes
Postscan
No action taken
Structured Text
Condition
Action Taken
Prescan
No action taken
Rung-condition-in is false
No action taken
Rung-condition-in is true
The instruction executes
Postscan
No action taken
Example
Ladder Diagram
SASI_LD__Example_v34
TIP:
The Sequence ID parameter can be a STRING tag in which the identifier is stored, or a quoted string containing up to 82 characters
Structured Text
if (SasiControl) then
SASI(Make_Product_101, IdString, Result);
end_if
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