Communication Between Central Units On The Cs 31 Bus; Cs 31 Bus Addressing; Communication Type - ABB AC 31 Technical Manual

5. Communication between central units on the CS 31 bus

5.1. CS 31 bus addressing

5.2. Communication type

ABB Control - AC 31
1SBC 260400 R1001-b 06.99
Program Optimization
The central units possess the CS 31 bus interface which may be used, just as well, as master
of the CS 31 bus or as slave of the CS 31 bus.
These configurations enable a considerable performance improvement by processing a part of
the process locally. The execution of the program is much faster and the availability of the
application is improved because a slave can continue with the partial control of the process
alone.
These configurations also enable the simplification of the conception, the setup as well as the
application maintenance by dividing the program into relatively independent parts.
The configuration as, master or slave, of a central unit is effectuated in the "Configuration "
menu of the AC31GRAF software "CONTROL PANEL (see Figure 6-6).
The authorized CS 31 addresses are:
Master central unit
50 series
90 series
Warning : You have also the possibility to use the CS31 bus in Modbus
configuration as Modbus
AC31GRAF software "CONTROL PANEL (see Figure 6-7).
See chapter 7 communication Modbus
A slave central unit is seen by the master central unit as a binary or analog input/output unit.
The number of data exchanged between the master and slave central units, on each CS 31
bus cycle, can be configured. This number should be adapted to the real data volume to be
transmitted in order to optimize the CS 31 bus communication times.
The maximum number for a bit configuration is 120 inputs and 120 outputs and the maximum
for an analog configuration is 8 word inputs and 8 word outputs.
This choice is made in the " CONTROL PANEL " "PLC configuration tool" menu of the
AC31GRAF software (see Figure 6-8).
binary
0 to 61
0 to 61
®
slave is also effectuated in the "Configuration " menu of the
®
.
Slave central unit
50 series 90 series
analog binary
0 to 61 0 to 61
0 to 5 and 0 to 61
8 to 15
analog
0 to 5 and
8 to 15
0 to 5 and
8 to 15
®
slave. This
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