Orb - Mitsubishi Electric MELSEC FX3U Programming Manual

FX /FX /FX Series Programmable Controllers
3G 3U 3UC
Programming Manual - Basic & Applied Instruction Edition
7.6

ORB

Outline
A circuit in which two or more contacts are connected in series is called serial circuit block.
1. Instruction format
ORB
OR Block
2. Applicable devices
Bit Devices
Instruc-
System User
tion
X Y M T C S D .b KnX KnY KnM KnS T C D R U \G
ORB
Explanation of function and operation
1. ORB instruction (parallel connection of multiple contact circuits)
When connecting serial circuit blocks in parallel, use LD or LDI instruction at the start of branch, and use
ORB instruction at the end of branch.
ORB instruction is an independent instruction not associated with any device number in the same way as
ANB instruction described later.
When there are many parallel circuits, ORB instruction can be used for each circuit block to connect them.
Circuit program
X000 X001
X002 X003
X004 X005
Serial circuit block
Caution
There is no limitation in the number of parallel circuits which can be connected by ORB instructions (in the
case of appropriate program shown above).
Though ORB instructions can be used at one time, note that the repeated use of LD or LDI instruction is
limited to 8 or less (in the case of inappropriate program shown above).
206
Mnemonic
Basic Instruction
ORB
1 step
−
Digit Specification
There are no applicable devices.
List program
Appropriate program
Y006
0000 LD
0001 AND X001
0002 LD
ORB instruction
0003 AND X003
0004
0005 LDI
0006 AND X005
0007
ORB instruction
0008 OUT Y006
Operation Condition
Continuous
Operation
Pulse (Single)
Operation
Word Devices
Special
System User
Unit
V Z Modify K H
Inappropriate program
X000 0000 LD
0001 AND X001
X002 0002 LD
0003 AND X003
ORB 0004 LDI
X004 0005 AND X005
0006
ORB 0007
0008 OUT Y006
7 Basic Instruction
Others
Con- Real Charac-
Index
stant Number ter String
E " "
X000
X002
X004
ORB
ORB
7.6 ORB
Pointer
P