ABB AC 31 - 2.1. Central units with extensions; 2.2. Central units with CS 31 bus; 2.3. Cabling techniques

Presentation / operation
ABB Control - AC 31 Page 1-5
1SBC 260400 R1001-b 06.99
2.1. Central units with extensions
The 40 and 50 series. It’s possible to increase the number of inputs / outputs of the basic
central unit by adding up to 6 local extension units of either type, binary or analog (Figure 1-1).
2.2. Central units with CS 31 bus
The 50 and 90 series. It’s possible to increase the number of inputs / outputs of the basic
central unit by adding remote units. The central unit controlling the system is called the
MASTER central unit. The maximum bus length is 500 m without an amplifier and 2000 m with
3 amplifiers (1 NCB or NCBR unit enables bus amplification for 500 m).
The master central unit can manage up to 31 connection points called SLAVES, such as:
- A remote unit with extension possibilities: a maximum of 6 extension units comprising of a
maximum of 8 analog input channels and 8 analog output channels
- A simple remote unit (without extension) with analog or binary inputs / outputs
- A remote TCAD display
- An ABB NCSA-01 variable speed drive interface
- A high speed counter unit
- A central unit (50 series with extension possibilities, 90 series and the previous 30 series)
- Or any other device which disposes of a CS 31 communication (see Figure 1-2).
Comment:
A slave fitted solely with binary channels occupies 1 connection point.
A slave fitted with binary and analog channels occupies 2 connection points of the available
31.
The maximum number of remote ANALOG units depends on the MASTER central unit:
- 50 series: - a maximum of 31 remote analog input units
- a maximum of 31 remote analog output units
- a maximum of 15 extensible remote units (ICMK14F1) with analog input / output
extensions + 1 remote analog input / output unit (15 x 2 + 1 = 31)
- or a mixed binary / analog configuration within the previous limits
- 90 series: - a maximum of 12 remote analog input units
- a maximum of 12 remote analog output units
- or a maximum of 12 slaves with analog extensions
Other Option: You have a possibility to use and configure the CS31 bus in Modbus
®
slave see
chapter 7 communication Modbus
®
.
2.3. Cabling techniques
Connecting a central unit without a remote unit is simple and corresponds to normal electrical
standards. The electrical connections of a AC 31 system which consists of remote units,
notably where there are numerous electrical cubicles, should adhere to the obligatory rules.
These rules are presented in chapter 4.