Configuring Modbus Communication; Setting The Modbus Network Address; Selecting The Communication Speed; Selecting The Parity Status - ABB LWT300 Series User Manual

Configuring Modbus communication

The following subsections refer to the Modbus configuration of your LWT300 instrument. You will also
find more information about Modbus registers in "Appendix B" on page B89.

Setting the Modbus network address

To set the instrument address so that it can be identified on a network:
1 Select Communication > Modbus > Address.
2 Press Edit.
3 Set an address between 1 and 247 and press OK (see "Setting a value" on page 35). Your
instrument should now appear on a network.

Selecting the communication speed

To set the instrument communication speed:
1 Select Communication > Modbus > Baud Rate.
2 Press Edit. A list of standard communication speeds (in bps) appears (1200, 2400, 4800, 9600, 19200).
3 From that list, select a baud rate compatible with your network.

Selecting the parity status

To set the communication protocol parity status:
1 Select Communication > Modbus > Parity.
2 Press Edit. A list of parity statuses appears (No Parity, Even, Odd)
3 From that list, select a parity status compatible with your network and press OK.

Selecting the stop bit

To set the communication protocol stop bit:
1 Select Communication > Modbus > Stopbit.
2 Press Edit. Available stop bits appear (1, 2)
3 From that list, select a stop bit compatible with your network and press OK.

Setting the response delay

The response delay is the length of time that must elapse before the LWT sends out a response. To
change this time:
1 Select Communication > Modbus > RespDelay Time.
2 Press Edit.
3 Set the response delay (see "Setting a value" on page 35) and press OK.

Selecting the register base number

The default Modbus register base number is 1. Should you need to change this base number:
1 Select Communication > Modbus > Address Offset.
2 Press Edit. A list of available base numbers appears (0, 1)
3 From that list, select the required base number and press OK.
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User Guide