Rockwell Automation 1772-LS_LSP,D17726.8.6 PROG/OPER MANUAL-MINI PLC-2/05 - Manual (Page 149)

Chapter
13
13-1
Jump Instructions and Subroutines
This chapter describes the instructions you can use to selectively jump over
portions of a program. The instructions are:
jump
jump to subroutine
label
return
This chapter describes how jump instructions and subroutine programming
direct the path of the program scan through the main program and the
subroutine area.
Jump/Jump to Subroutine/Return Instructions
Purpose: A Jump instruction is an output instruction. It has an
identification number from 00-07. When its rung is true, it instructs the
processor to jump forward in the main program to the Label instruction
having the same identification number. The main program executes from
that point.
010
00
JMP
01
Jump
You can reduce scan time by selectively jumping over a portion of the
program. Do not program in an area where the jump instruction crosses
the boundary between the main program and subroutine area, or
vice-versa.
ATTENTION: Allowances should be made for conditions
which could be created by the use of the Jump instruction.
Jumped program rungs are not scanned by the processor. Input
conditions are not examined and outputs that are controlled by
these rungs remain in their last state. Timers and counters cease
to function. Critical rungs should be re-programmed outside the
jumped section in the program zone.
Chapter Objectives