User guide

Configuring an M1 CPU with Concept
870 USE 101 00 V.2.2
273
Changing Mode and Data Bits
Introduction
From the Modbus Port Settings dialog box, each port can be configured to operate
in one of two possible modes – RTU or ASCII.
If the mode is RTU, the number of data bits is always 8.
If the mode is ASCII, the number of data bits is always 7.
Note:
The factory-set default is 8-bit RTU.
Procedure
To change the mode and data bit parameters, perform the steps in the following
table.

Step Action
1 Click on the down arrow under Mode.
Result:
A menu appears displaying your two Mode options.
2 Click on the
RTU
or
ASCII
entry.
Result:
The Ports setting Window is updated with the Mode type you have
specified, the corresponding Data Bit value appears.
Example:
If you change Modbus Port 1 from RTU mode to ASCII mode, the Data
Bit value also automatically changes from 8 to 7.