Specify a non-retentive assignment
The non-retentive assignment is different from the regular assignment described above in that the tag in a non-retentive assignment is reset to zero each time the controller:
- Enters the Run mode
- Leaves the step of an SFC if you configure the SFC for Automatic reset. This applies only if you embed the assignment in the action of the step or use the action to call a structured text routine by using a JSR instruction.
A non-retentive assignment has this syntax:
tag [:=] expression ;
where:
Component | Description | |
tag | Represents the tag that is getting the new value; the tag must be a BOOL, SINT, INT, DINT, STRING, or REAL. Tip: The STRING tag is applicable to CompactLogix 5380, CompactLogix 5480, ControlLogix 5580, Compact GuardLogix 5380, and GuardLogix 5580 controllers | |
[:=] | Is the non-retentive assignment symbol. | |
expression | Represents the new value to assign to the tag. | |
If tag is this data type | Use this type of expression | |
BOOL | BOOL | |
SINT | Numeric | |
INT | ||
DINT | ||
REAL | ||
STRING ( CompactLogix 5380, CompactLogix 5480, ControlLogix 5580, Compact GuardLogix 5380, and GuardLogix 5580 controllers | String type, including string tag and string literal CompactLogix 5380, CompactLogix 5480, ControlLogix 5580, Compact GuardLogix 5380, and GuardLogix 5580 controllers | |
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