Rockwell Automation 1761-HHP-B30 MicroLogix 1000 with Hand-Held Programmer (HHP) - Manual (Page 125)

Chapter 8
Using Basic Instructions
8–6
The LDT and ORT instructions are used to short circuit a block of logic.
They are useful for debugging a rung when you need a condition that is
always true.
There are no parameters to enter for these instructions.
Using LDT
Use the LDT instruction to place a short in the first position of a rung or
block. This instruction can only be used if it is immediately used with an OR
or ORB instruction.
Entering the Instruction
You enter the instruction from within the program monitor functional area.
P 0 0 0 L D T
Using ORT
Use the ORT instruction to place a short in parallel with any previous input
instruction in the current rung or block.
Entering the Instruction
You enter the instruction from within the program monitor functional area.
P 0 0 0 O R T
] [
] [
False
1.54
Execution Times (
µ
sec) when:
True
n/a LDT
1.94 n/a ORT
Ladder representation:
LDT
ORT
Load True (LDT) and Or True
(ORT)
6 2
L
To enter the function code, press:
FUN ENT
7 2
L
To enter the function code, press:
FUN ENT