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Rockwell Automation 1772-L8_LW_LWP_LX_LXP,D17726.5.8 User Manual User Manual

Page 132

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RelayĆLike Instructions

Chapter 9

9-6

Editing in a Completed Rung

Edit the Output Energize instruction by performing the following steps.
However, you cannot remove an output instruction.

1.

Position the cursor over the Output Energize instruction you want
to change.

2.

Press –( )– or any other appropriate output instruction key.

3.

Enter

.

The Output Latch –(L)– instruction tells the processor to latch and set a
specified data table bit when the rung is true. It is usually paired with an
unlatch instruction.

113

04

L

010

00

Bit Controlling

Output Latch

The Output Unlatch –(U)– instruction tells the processor to unlatch and
reset a specific data table bit. It is usually paired with a latch instruction.

113

05

U

010

00

Bit Controlling

Output Unlatch

Important: The conditions for the Output Unlatch instruction must be
different from the conditions that precede the Output Latch instruction.

These are retentive instructions. Retentive means that when the rung
condition goes false, the latched bit remains set and the unlatched bit
remains reset until changed by the program.

These instructions control a specific bit based on the rung condition.
When its rung conditions are:

True - Output Latch sets a specified bit.
True - Output Unlatch resets a specified bit.
False - No action is taken.

Output Latch/Unlatch