AutomationDirect DL105, User Manual

Page: 163 / 350

Standard
RLL
Instructions
5--3
Standard RLL Instructions
Boolean Instructions
DL105 PLC User Manual, 3rd Edition
Using Boolean Instructions
Do you ever wonder why so many PLC manufacturers always quote the scan time
for a 1K boolean program? Simple. Most all programs utilize many boolean
instructions. These are typically very simple instructions designed to join input and
output contacts in various series and parallel combinations. Our Direct SOFT
software is a similar program. It allows you to use graphic symbols to develop the
program; therefore, you don’t necessarily have to know the instruction mnemonics in
order to develop a program.
Many of the instructions in this chapter are not program instructions used in
Direct SOFT, but are implied. In other words, they are not actually keyboard
commands, however, they can be seen in a Mnemonic View of the program once the
Direct SOFT program has been developed and accepted (compiled). Each
instruction listed in this chapter will have a small chart to indicate how the instruction
is used with Direct SOFT and the HPP.
DS
Implied
HPP Used
The following paragraphs show how these instructions are used to build simple
ladder programs.
All DL105 programs require an END statement as the last instruction. This tells the
CPU that this is the end of the program. Normally, any instructions placed after the
END statement will not be executed. There are exceptions to this such as interrupt
routines, etc. This chapter will discuss the instruction set in detail.
OUT
Y0 X0
END
All programs must have
and END statement
You use a contact to start rungs that contain both contacts and coils. The boolean
instruction that does this is called a Store or, STR instruction. The output point is
represented by the Output or, OUT instruction. The following example shows how to
enter a single contact and a single output coil.
OUT
Y0 X0
END
Direct SOFT Example Handheld Mnemonics
STR X0
OUT Y0
END
END Statement
Simple Rungs