Read M-Bus meters over RS485

The following list instructs how to configure a PiiGAB M-Bus 900/900S so that M-Bus meters can be read with RS485.

1. Start the gateway’s web interface in any web browser.
2. Go to the Configuration page.
3. Select any slave port for the RS485 communication.
4. Specify the following parameters:
   • Type: Serial.
   • Com port: RS-485.
   • Baud rate: The specified communication speed on the RS485 bus.
   • Bit Number: Number of data bits on the RS485 bus.
   • Parity: The parity for the RS485 bus.
   • Stop Bit: Number of stop bits on the RS485 bus.
   • Timeout: Expected time to get answer from the M-Bus meter.
   • Protocol: The data protocol on the RS485 bus.
5. Press the Save settings.
6. Connect the RS485-cable to the the gateways pin 8 (A) and 9 (B).

The picture shows Slave port 2 is configured for RS485 on 2400 baud, 8 data bits, even parity, 1 stop bit, 2000ms as timeout and M-Bus communication.

Note:

• Make sure the gateway doesn’t use the RS485-port anywhere else. For instance any other slave ports or the Modbus2MBus and/or the Wireless applications.
• The A and B pins should likely go to the opposite A and B on the RS485 master.
  Exempelvis: A->A och B->B.