Output Unlatch (Otu); Relay Ladder; Structured Text - Allen-Bradley Logix5000 Reference Manual

Chapter 2 Bit Instructions (XIC, XIO, OTE, OTL, OTU, ONS, OSR, OSF, OSRI, OSFI)

Output Unlatch (OTU)

Description:
Arithmetic Status Flags:
Fault Conditions:
Condition
Prescan
Rung-condition-in is false
Rung-condition-in is true
Postscan
100
The OTU instruction clears (unlatches) the data bit.
Operands:

Relay Ladder

Operand
Data bit

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
expressions, and assignments within structured text.
When enabled, the OTU instruction clears the data bit. When disabled, the
OTU instruction does not change the status of the data bit.
Not affected
None
Execution:
Relay Ladder Action
The data bit is not modified.
The rung-condition-out is set to false.
The data bit is not modified.
The rung-condition-out is set to false.
The data bit is cleared.
The rung-condition-out is set to true.
The data bit is not modified.
The rung-condition-out is set to false.
Rockwell Automation Publication 1756-RM003N-EN-P - October 2011
Type Format
BOOL Tag
for information on the syntax of constructs,
Description
Bit to be cleared