4ć14, 4 operating instructions – Rockwell Automation 1772-LP3 PLC - 2/30 Programmable Controller Programming and Operations Manual User Manual

Page 78

Introduction to Programming

Chapter 4

4Ć14

Table 4.A

RelayĆType Instructions

NOTE: Examine and Output addresses, XXX/XX, can be assigned to any location in the Data Table, excluding the processor work areas. The word

address is displayed above the instruction and the bit number below it. To enter a bit address larger than 5 digits, press the [EXPAND ADDR] key after

the instruction key and then enter the bit address. Use a leading zero, if necessary.

Keytop Symbol

Instruction Name

1770ĆT3 Display

Description

-|ă|-

EXAMINE ON

XXX

-|ă|-

ăXX

When the addressed memory bit is ON, the instruction is

TRUE.

-| / |-

EXAMINE OFF

ĂXXX

-| / |-

ĂăXX

When the addressed memory bit is OFF, the instruction is

TRUE.

-(ă)-

ENERGIZE

XXX

-(ă)-

ăXX

When the rung is TRUE, the addressed memory bit is set

ON. If the bit controls an output device, that output device

will be ON.

-( L )-

OUTPUT LATCH

ăXXX

-( L )-

ONĂ XX

or OFF

When the rung is TRUE, the addressed memory bit is

latched ON and remains ON until is is unlatched. The

OUTPUT LATCH instruction is initially OFF when entered,

as indicated below the instruction. It can be preset ON by

pressing a [1] after entering the bit address. An ON will

then be indicated below the instruction in PROGRAM

mode.

-( U )-

OUTPUT UNLATCH

ĂăXXX

-( U )-

ONĂ XX

or OFF

When the rung is TRUE, the addressed bit is unlatched.

If the bit controls an output device, that device is

deenergized. ON or OFF will appear below the instruction

indicating the status of the bit in PROGRAM mode only.

BRANCH START

This instruction begins a parallel logic path and is entered

at the beginning of each parallel path.

BRANCH END

This instruction ends two or more parallel logic paths and

is used with BRANCH START instructions.

These instructions should not be assigned Input Image Table addresses because Input Image Table words are reset each I/O scan.

This section contains the operating instructions that are used to move
through the program and perform a variety of functions.

Addressing
Help

directories

Searching
Editing
On-line

programming

Clearing

memory

4.4
Operating Instructions