Mitsubishi Electronics FX1S manual Or Block, Batch processing limitations

FX Series Programmable Controllers Basic Program Instructions 2

2.11Or Block

FX1S FX1N FX2N FX2NC

Mnemonic	Function	Format	Devices	Program steps
ORB	Parallel connection		N/A	1
	of multiple contact
(OR Block)
	circuits

Program example:

X0 X1

X2 X3

X4 X5

Y6

ORB

ORB

Recommended sequential				Non-preferred batch
programming method				programming method
0	LD	X	0	0	LD	X	0
1	AND	X	1	1	AND	X	1
2	LD	X	2	2	LD	X	2
3	AND	X	3	3	AND	X	3
4	ORB			4	LDI	X	4
5	LDI	X	4	5	AND	X	5
6	AND	X	5	6	ORB
7	ORB			7	ORB	Y	6
8	OUT	Y	6	8	OUT

Basic points to remember:

-An ORB instruction is an independent instruction and is not associated with any device number.

-Use the ORB instruction to connect multi-contact circuits (usually serial circuit blocks) to the preceding circuit in parallel. Serial circuit blocks are those in which more than one contact connects in series or the ANB instruction is used.

-To declare the starting point of the circuit block use a LD or LDI instruction. After completing the serial circuit block, connect it to the preceding block in parallel using the ORB instruction.

Batch processing limitations:

• When using ORB instructions in a batch, use no more than 8 LD and LDI instructions in the definition of the program blocks (to be connected in parallel). Ignoring this will result in a program error (see the right most program listing).

Sequential processing limitations:

• There are no limitations to the number of parallel circuits when using an ORB instruction in the sequential processing configuration (see the left most program listing).

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