GE GFK0579B user manual Ïïïï Rïïïïïïï

1

HA Remote I/O Scanner can be located on a bus stub. The bus switching device to which the bus stub is connected can be another Remote I/O Scanner, as shown below, or a Genius block with a Bus Switching Module attached.

In this example, there are two remote drops installed directly on a dual bus. A third remote drop and some Genius blocks are installed on a bus stub connected to one of the Remote I/O Scanners. That Remote I/O Scanner acts as the bus switching device. A remote drop on a bus stub can accommodate up to 128 bytes of inputs and 128 bytes of outputs, and may include expansion racks.

RACK 0

PS S C A

N

N

E

R

BUS A

RACK 0 a44880

PS S C A N

N

E

R

BUS B	RACK 0
	P S
	S C
BUS	A
	ÏÏÏÏRÏÏÏÏÏÏÏ
STUB	N
	N
	E

HFinally, a remote drop can be located on just one bus of a redundant bus pair, if bus redundancy is not needed for the modules in that remote drop.

In this example, the remote drop on the right is connected to both Bus A and Bus B; the remote drop on the left, which contains non±critical I/O modules, is connected to Bus A only.

RACK 0

PS S C A N N E R

RACK 0 a44877

PS S C A N

N

E

R

BUS A

BUS B

Chapter 1 Introduction 17