Ladder Symbols In Structured Ladder/Fbd Language - Mitsubishi Electric MELSEC Q Series Programming Manual

Ladder symbols in structured ladder/FBD language

The following table shows the ladder symbols that can be used in the structured ladder/FBD language.
For details, refer to the following manual.
 MELSEC-Q/L Structured Programming Manual (Common Instructions)
Element Ladder symbol
*1*2
Normal
*1*2
Negation
*1*2*3
Rising edge
*1*2*3
Falling edge
*1*2*3
Negated rising edge
*1*2*3
Negated falling edge
*1
Normal
*1
Negation
*1
Set
*1
Reset
Jump
Return
Function
Function block
Function argument input
Description
Turns ON when a specified device or label is ON
Turns OFF when a specified device or label is OFF.
Turns ON at the rising edge (OFF to ON) of a specified device or label.
Turns ON at the falling edge (ON to OFF) of a specified device or label.
Turns ON when a specified device or label is OFF or ON, or at the falling edge (ON to OFF) of a specified
device or label.
Turns ON when a specified device or label is OFF or ON, or at the rising edge (OFF to ON) of a specified
device or label.
Outputs the operation result to a specified device or label.
A specified device or label turns ON when the operation result turns OFF.
A specified device or label turns ON when the operation result turns ON.
Once the device or label turns ON, it remains ON even when the operation result turns OFF.
A specified device or label turns OFF when the operation result turns ON. If the operation result is OFF,
the status of the device or label does not change.
Pointer branch instruction
Unconditionally executes the program at the specified pointer number in the same POUs.
Indicates the end of a subroutine program.
Executes a function.
Executes a function block.
Inputs an argument to a function or function block.
5 WRITING PROGRAMS
5.2 Structured Ladder/FBD
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