Cutler-Hammer D320 PLC, User Manual

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D320 PLC User's Manual
Instruction
Mnemonic Jump by Pointer Range
Bit
Word
JMP
LBL JMP: Jump by pointer
LBL: Specify the pointer
Double words
Ladder
JMP: Jump to the LBL instruction L (L = 0 to 63).
LBL: Position jumped to by the JMP instruction.
Description
1. This instruction is used to conditionally perform a set of instructions in the program. When
the input condition to the JMP instruction is true, execution will jump over the following
instructions, directly to the corresponding LBL label. When the input condition is false, the
instructions following the JMP will be executed normally, and no jump occurs.
2. The range of L is 0 to 63, allowing 64 jumps to be used.
3. The given L label may only be used once in a program. It may not be duplicated.
4. For a given JMP with parameter L, there MUST be a corresponding LBL with the same L
value. Also, the LBL instruction must come after the JMP instruction in the program. If either
of these two conditions is not satisfied, an error will occur preventing execution of the
program.
5. This operation will occur on every scan for which the input condition is true (On). To perform
the operation only on a change of input condition, use the rising/falling edge contact.
Example
Program Expression Operation Results
When contact R0.0 turns On, JMP 1 occurs, and
execution jumps directly to LBL 1—the instructions
between the JMP and LBL are not executed.
When contact R0.1 turns On, execution of the
program jumps directly from JMP 3 to LBL 3.
JMP
L =
LBL
L =
R
(OUT)
JMP
L = 1
JMP
L = 3
R0.0
R
R0.1
R
LBL
L = 3
LBL
L = 1