ABB Energy Meters
Supported Devices
| Device Type | Modbus TCP (Ethernet) | RS485 |
|---|---|---|
| ABB B21 | ❌ | ✅ |
| ABB B23 | ||
| ABB B24 |

Wiring
RS485
The ABB B-series meters (B21, B23, B24) use a 3-pole RS485 connection. Connect these to the Controller as follows, based on the meter's terminal markings.
1. Device (ABB Meter) Pinout
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 Controller 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.
2. Controller & Converter Pinout
This table shows the corresponding RS485 pins on SmartgridOne controllers and converters. Match the 'A' and 'B' from the meter (see table above) to the 'A' and 'B' on your controller.
RS485 Wiring
- For correct RS485 wiring: Follow the guidelines for RS485 wiring.
- If the wiring shown in the table below is incorrect, please let us know.
- There is no general consensus in the industry about the usage of A and B for the RS485 polarity, so it may be counterintuitive and opposite of what you might expect for some devices.
| Device | SmartgridOne Controller model OM1 | SmartgridOne Controller 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 |
Configuration
NOTE: RS485 Device Addresses
- You MUST give each device on the RS485 bus a unique address. Check the manual of the device on how to do this.
- Use lower addresses first (1, 2, ...) because the SmartgridOne Controller will find them faster!
- For each device, it is generally recommended to stick with the factory default baud rate, parity, and stop bits. The SmartgridOne Controller will scan on those first.
Use the following Modbus settings in the Controller's device wizard. These are the default settings for the meter:
- Baudrate: 19200
- Modbus Address: 1 (or the address set on the meter)
- Parity: Even
- Stop bits: 2
