Programming; Bit Transmission - ABB AC 31 Technical Manual

5.3. Programming

Page 6-14
Program Optimization
Data exchange may be carried out directly through the inputs/outputs or by using function
blocks.
Exchange through inputs/outputs is particularly well adapted with a low number of data.

5.3.1. Bit transmission

CU master
Figure 6-9 : Bit transmission
The master central unit will receive the binary information from the slave central unit in the
Ixx.00 to Ixx+N.15 inputs, N+1 being the number of bits to transmit from the slave central unit
to the master slave unit modulo 16.
The slave unit will send the information through the O00.00 to ON.15 outputs.
The master central unit will send the binary information to the slave central unit through the
Oxx.00 to O(xx+M).15 outputs, (M+1) being the number of bits to transmit from the master
central unit to the slave central unit modulo 16.
The slave central unit will receive this information in the I00.00 to IM.15 inputs.
The N and M values may be different.
For example : The transmission of the "VALUE_M00" bit value from the slave 20 central unit to
the master central unit and the transmission of the "VALUE_FOR_SLAVE" bit value from the
master central unit to the slave 20 central unit.
CS 31 bus
CU slave
Address xx
ABB Control - AC 31
1SBC 260400 R1001-b 06.99