ABB Energy Meters
| Device Type | Modbus TCP (Ethernet) | RS485 |
|---|---|---|
| ABB B21 | ❌ | ✅ |
| ABB B23 | ||
| ABB B24 |
The ABB B-series meters (B21, B23, B24) use a 3-pole RS485 connection. Connect these to the EMS as follows, based on the meter's terminal markings.
This table shows the terminals on the meter itself.
| Signal | Terminal Number |
|---|---|
| A | 37 |
| B | 36 |
| C (GND) | 35 |
IMPORTANT: Troubleshooting
The 'A' and 'B' labels are not universally standardized. If the EMS cannot find the device during a scan, it is often due to a wiring mismatch.
Swap the A and B wires (between the controller and the meter) and try scanning again.
This table shows the corresponding RS485 pins on Sofar controllers and converters. Match the 'A' and 'B' from the meter (see table above) to the 'A' and 'B' on your controller.
| Device | Sofar EMS model OM1 | Sofar EMS model IG8 | RS485-USB converter | RS485-Ethernet converter |
|---|---|---|---|---|
| A | RS485 A | RS485_POS | RS485 A | TX+ |
| B | RS485 B | RS485_NEG | RS485 B | TX- |
| N/A | RS GND | GND | Not available | G |
Use the following Modbus settings in the EMS's device wizard. These are the default settings for the meter: