Andover Controls DI-8 - Page 21

Continuum I/O System Reference 15
CPU with local and several remote I/O Modules:
The I/O Bus that needs to be terminated is the one formed by the cable that starts at
the NetController and ends at the first remote module. The bus that extends from the
NetController through the local I/O stack and the one that starts at the first remote
module and extends through subsequent modules do not need termination. In this
case, the terminator resistor is connected directly across the communications lines
(pins 1 & 2) at the NetController and again at the first remote I/O module.
CPU
5
4
3
2
1
5
4
3
2
1
120 Ω
Resistor
120 Ω
Resistor
Remote
I/O
Module
5
4
3
2
1
Local
I/O
Local
I/O
Remote
I/O
Module
5
4
3
2
1
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