General Setup Rules - ABB AC 31 Technical Manual

2. General setup rules

ABB Control - AC 31
1SBC 260400 R1001-b 06.99
Presentation / operation
An ABB AC 31 system always includes an AC 31 central unit. There are three types of central
units:
- The 40 series central unit, with a local inputs / outputs extensions interface
- The 50 series central unit, with a local inputs / outputs extensions interface
and a CS 31 bus interface
- The 90 series central unit, with a CS 31 bus interface
Each central unit incorporates a specific number of binary inputs / outputs and occasionally
analog. It is possible, depending on the central unit, to increase the number of inputs / outputs,
to add input / output extensions connected directly to the central units or remote input / output
units via the CS 31 twisted pair.
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