MITSUBISHI ELECTRIC 700 Series - Manual (Page 70)

65
Programming Languages
3
SEQUENCE PRO
G
RAM
M
ING
3.4 Programming Languages
The built-in PLC function has two different programming methods: one that uses
ladders and the other that uses dedicated instructions.
• Programming that uses ladders is performed in the relay symbolic language. *1
• Programming that uses dedicated instructions is performed in the logic symbolic
language. *2
Whether the relay symbolic language or logic symbolic language is used, the same
program is created.
3.4.1 Relay symbolic language (Ladder mode)
The relay symbolic language is based on the concept of a relay control circuit.
You can perform programming in the representation close to the sequence circuit of
relay control.
(1) Ladder block
A ladder block is the minimum unit for performing sequence program operation. It
starts with the left hand side vertical bus and ends with the right hand side vertical
bus.
Fig 3.2 Ladder Blocks
REMARKS
*1. When using GX Developer for programming, perform programming in the "ladder mode".
*2. When using GX Developer for programming, perform programming in the "list mode".
Right hand
side vertical
bus
Ladder
blocks
Left hand side vertical bus
Step number
* X0 to X5: Indicate inputs.
Y10 to Y14: Indicate outputs.