GE GFK0579B user manual Genius Bus Connections Dual Bus Cables, Dual Bus Termination

2

Genius Bus Connections: Dual Bus Cables

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.

	SER1	1	2	SHIELD
				IN
	SER2	3	4	SHIELD
				OUT
	SER1A	5	6	SHIELD
R				IN A
E				SHIELD
D	SER2A	7	8
U				OUT A
N
D				SHIELD
A	SER1B	9	10
				IN B
N
C
Y	SER2BÓÑ11		12	SHIELD
				OUT B

a44881

TERMINALS

FOR

BUS A

TERMINALS

FOR

BUS B

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.

Dual Bus Termination

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).

Chapter 2 Installation 33