CONCEPT MESSAGE.

Connecting to ABB B23 Modbus energymeter.

• • • Using Digitus USB-RS485 adapter
    • A-B are swapped as found here
    • No bus terminating resistors used (only 2 participants on bus, usb-rs485 and abb b23)
    • User Manual found here

I have the USB-RS485 plugged into a Debian Linux pc system (x86_64). I used the ModPoll tool from modbusdriver.com for basic connection testing.

#./modpoll /dev/ttyUSB0 -b 9600 -p none -m rtu -a 1 -r 23296 -t 4:int -c 6

• Offset addres 23296 (or hex 0x5B00) should have L1-N voltage.
• Read 6 next values also (-c 6)
• Gave me L-to-N and L-to-L voltages.

Wrote a small C application to poll every second and write to MariaDB/MySQL database table. Should be possible to recompile for Raspberry-PI (ARM) to.

Uses libmodbus(-dev) and libmariadbclient(-dev).

See attachments.