Introduction

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

Examine If Closed (XIC)

Operands:

The XIC instruction examines the data bit to see if it is set.

Relay Ladder

Operand

data bit

Type

BOOL

Format

tag

Description

bit to be tested

Structured Text

Structured text does not have an XIC instruction, but you can achieve the same results using an IF...THEN construct.

IF data_bit THEN

<statement>;

END_IF;

See Appendix 641B, Function Block Attributes for information on the syntax of constructs within structured text.

Description:

The XIC instruction examines the data bit to see if it is set.

Arithmetic Status Flags:

not affected

Fault Conditions:

none

Execution:

Condition

prescan rung-condition-in is false rung-condition-in is true

Relay Ladder Action

The rung-condition-out is set to false.

The rung-condition-out is set to false.

examine data bit data bit = 0 rung-condition-out is set to false data bit = 1 postscan

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rung-condition-out is set to true end

The rung-condition-out is set to false.

Publication 1756-RM003K-EN-P - July 2008

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

Example 1:

If limit_switch_1 is set, this enables the next instruction (the rung-condition-out is true).

Relay Ladder

Structured Text

IF limit_switch THEN

<statement>;

END_IF;

Example 2:

If S:V is set (indicates that an overflow has occurred), this enables the next instruction (the rung-condition-out is true).

Relay Ladder

Structured Text

IF S:V THEN

<statement>;

END_IF;

Publication 1756-RM003K-EN-P - July 2008

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