GE GFK0579B User Manual

To install a Remote I/O Scanner directly on both busses of a redundant bus, use the
lower eight terminals as described below.  Do not attach an external Bus Switching Module
to a Remote I/O Scanner.

TERMINALS

FOR

BUS A

TERMINALS

FOR

BUS B

5

6

3

1

7

9

11

4

2

8

10

12

ÑÑÑ

ÑÑÑ

ÑÑÑ

ÑÑÑ

ÓÓÓ

ÓÓÓ

ÓÓÓ

ÓÓÓ

R
E
D
U
N
D
A
N
C
Y

SER1

ÎÎÎ

ÎÎÎ

SER1A

ÎÎÎ

ÎÎÎ

SER2A

ÎÎÎ

ÎÎÎ

SER1B

ÎÎÎ

ÎÎÎ

SER2B

a44881

ÓÓ

ÓÓ

ÓÓ

ÓÓ

ÑÑ

ÑÑ

ÑÑ

ÑÑ

ÎÎ

ÎÎ

SHIELD

OUT B

ÎÎ

ÎÎ

SHIELD

IN B

ÎÎ

ÎÎ

SHIELD

OUT A

ÎÎ

ÎÎ

SHIELD

IN A

SHIELD

IN

SHIELD

OUT

SER2

1.

Connect bus A to terminals 5 – 8 on the Remote I/O Scanner, marked SER1A,
SER2A, SHIELD IN A and SHIELD OUT A.

2.

Connect bus B to terminals 9 – 12, marked SER2A, SER2B, SHIELD IN B, and
SHIELD OUT B.

3.

For each bus, connect Serial 1 to the Serial 1 terminals of the previous device and
the next device.  Connect Serial 2 to the Serial 2 terminals of the previous device
and the next device.

4.

For each bus, connect the appropriate Shield In terminal to Shield Out of the
preceding device.  Connect Shield Out to Shield In of the next device.  If the
Remote I/O Scanner is the first device on a bus, its Shield In terminal for that bus
can be left unconnected.  If it is the last device on the bus, its Shield Out terminal
for that bus can be left unconnected.

When making bus connections, the maximum exposed length of bare wires should be
two inches.  For added protection, each shield drain wire should be insulated with
spaghetti tubing to prevent the Shield In and Shield Out wires from touching each
other or the signal wires.

If either trunk cable of the dual bus ends at the Remote I/O Scanner, install a
terminating resistor across the Serial 1 and Serial 2 terminals where that cable attaches
to the module.  If both cables terminate at the Remote I/O Scanner, each must have its
own terminating resistor. Do not terminate dual bus stubs (see next page).