User Manual

10.9 Potential Equalization

The difference between the actual physical voltage potentials

DGND of all connections with the bus must not exceed ±7 Volt.

If this cannot be guaranteed, an equalization has to be

provided. For most of the connections this means that the

minus connection of the power supply has to be fed-through as

a compensating line from connection to connection.

10.10 Adjustment of Address and Baud Rate

Before a control unit (PLC) or a computer (PC) can interchange

data with a data logger via the bus, address and baud rate for

the data logger have to be defined. Following hints have to be

considered:

 All devices have to be adjusted to the same baud rate.

 Within the bus topology the same address must not ap-

pear twice.

bus parameter ASCII-protocol /

MODBUS-Protocol

PROFIBUS-protocol

address 1 ..... 127 1 ..... 126

2,400 bps -

baud rate 4,800 bps -

9,600 bps 9,600 bps

19,200 bps 19,200 bps

38,400 bps -

Table 10.3 Setting variants for address and baud rate

for the data logger COMBILOG 1022

Hardware Manual COMBILOG 1022