ABB ACS310 Quick Start Manual page 23

Quickstart Guide
ABB PLC and drives integration using Modbus RTU
Double‐click "COMX_Modbus" to configure the Modbus settings. Do at least the following settings:

Set "Baudrate", "Parity", "Data bits" and "Stop bits" (1) according to settings in actual drive.

Set "Operation mode" to "Master" and "Address" to "0" (2).

Set "RTS control" to "Telegram" (3)
(=RS485 ‐ in AC500‐eCo this is already set)
Modbus RTU ‐ 23 ‐ PLC and drives integration