Configuring Modbus interface - AQT530

AQT530 Configuration Guide

Document code
M212572EN
Revision
D
Language
English (United States)
Product
AQT530
Document type
User guide
The default communication settings are listed in the following table. Use the settings that are suitable for you.
Table 1. Modbus interface configuration parameters
Parameter Type Range Default Unit Description
rs485_mode uint8
  • 0 = ASCII CSV
  • 1 = Modbus ASCII
  • 4 = Modbus RTU
4 RS-485 mode
rs485_addr uint8 1 ... 253 1 Modbus address (not used in ASCII CSV mode)
rs485_baud uint32 4800 ... 115200 19200 bps RS-485 baud rate
rs485_databits uint8 7, 8 8 bits RS-485 data bits
rs485_parity Text
  • N = None
  • E = Even
  • O = Odd
E RS-485 parity

Case insensitive

rs485_stopbits uint8 1, 2 1 bits RS-485 stop bits
  1. Establish a connection to AQT530.
  2. Using a terminal program, define the settings for the RS-485 interface.
    • To use the RS-485 port in Modbus ASCII mode, type the following:

      set rs485_baud=9600
      set rs485_mode=1
      set rs485_databits=7
      set rs485_parity=e
      set rs485_stopbits=1
      write --really
      • Bit rate: 9600 bps
      • Mode: ASCII
      • Port settings: 7E1 (7 data bits, even parity, 1 stop bit)
    • To use the RS-485 port in Modbus RTU mode, type the following:

      set rs485_baud=19200
      set rs485_mode=4
      set rs485_databits=8
      set rs485_parity=e
      set rs485_stopbits=1
      write --really
      • Bit rate: 19200
      • Mode: RTU
      • Port settings: 8E1 (8 data bits, even parity, 1 stop bit)
  3. The device is ready.