Allen-Bradley Logix5000 - Output Unlatch (OTU); Relay Ladder; Structured Text

100 Rockwell Automation Publication 1756-RM003N-EN-P - October 2011
Chapter 2 Bit Instructions (XIC, XIO, OTE, OTL, OTU, ONS, OSR, OSF, OSRI, OSFI)
Output Unlatch (OTU)
The OTU instruction clears (unlatches) the data bit.
Operands:
Relay Ladder
Structured Text
Structured text does not have an OTU instruction, but you can achieve the same
results by using an IF...THEN construct and an assignment.
IF BOOL_expression THEN
data_bit := 0;
END_IF;
See Function Block Attributes
for information on the syntax of constructs,
expressions, and assignments within structured text.
Description: When enabled, the OTU instruction clears the data bit. When disabled, the
OTU instruction does not change the status of the data bit.
Arithmetic Status Flags: Not affected
Fault Conditions: None
Execution:
Operand Type Format Description
Data bit BOOL Tag Bit to be cleared
Condition Relay Ladder Action
Prescan The data bit is not modified.
The rung-condition-out is set to false.
Rung-condition-in is false The data bit is not modified.
The rung-condition-out is set to false.
Rung-condition-in is true The data bit is cleared.
The rung-condition-out is set to true.
Postscan The data bit is not modified.
The rung-condition-out is set to false.