Yaskawa MP900 Series Machine Controller for Standard Operation - Manual (Page 390)

7.3 Creating Ladder Logic Programs
7-23
7
• Structure of ladder instructions
• Ladder instruction input methods
• Operand input methods
• Inputting instructions
„ Structure of Ladder Instructions
Basically, ladder instructions consist of three elements: A symbol, a numeric processing
instruction or register number, and a bit processing instruction or current value.
For current values expressed as bit processing instructions, the text will be displayed in bold
if the condition of the bit processing instruction is met and will be displayed in normal text is
the condition is not met.
The register value is displayed for numeric processing instructions. The current value is dis-
played only in Online Mode.
„ Inputting Ladder Instructions
There are three methods that can be used to input ladder instructions. Use the methods as
required to facilitate inputting.
Refer to MP900 Series Machine Controller User's Manual: Ladder Programming (SIEZ-
C887-1.2C) for details on instructions. Refer to the list of instructions that can be entered
located in Appendix C Drawing and Function Instructions.
Using Mnemonics
Instructions can be selected easily from the keyboard by inputting mnemonics and pressing
the Enter Key. These mnemonics eliminate the need to search for the instruction on pull-
down menus or the function bar. Refer to Appendix C Drawing and Function Instructions
for lists of mnemonics.
As an example, the procedure to select the N.O. CONTACT instruction (-| |-) is described
Basic Structure of Ladder Instruction
Symbol
Register number or
numeric processing
instruction
Current value or bit
processing instruction
Input/Not displayed
Input/Not displayed
Input/Not displayed
LIMIT-SW
MB00101 IN-DATA
MW00100
01000
Bit processing
instruction
Numeric processing
instruction
Symbol Symbol
Register No. Register No.
Bit instruction Current value
Displayed in bold text if condi-
tion is met in Online Mode.