Check the installation
- Confirm that A and B are connected consistently across the RS485 bus.
- Confirm that baud rate, parity, stop bits, and Modbus address match the connected equipment.
- Disconnect other devices temporarily to rule out a bus wiring, addressing, or termination problem.
Run the built-in RS485 self-test
The self-test runs inside the affected SB1000 and cannot be started from the public WordPress site.
- Open the affected SB1000 web interface and go to Help → Serial Broker – Troubleshooting.
- Disconnect both RS485 ports from the field bus.
- Connect Port 1 A to Port 2 A.
- Connect Port 1 B to Port 2 B.
- Start the RS485 self-test shown in the device Help page and follow its result.
If the device web interface is unavailable, resolve the power or network connection first. If the self-test fails with only the loopback wiring connected, record the result and contact Varibits support.
- After connecting the cable, allow a few seconds for the Ethernet link to come up before treating it as a failure.
- Try a known-good Ethernet cable and another switch port.
- Check the switch for Energy Efficient Ethernet (EEE) or “green Ethernet” behaviour. Temporarily disabling that feature on the relevant port can help identify a compatibility issue.
- Check the SB1000 network settings and confirm whether it received the expected address from DHCP.
If the link still does not appear, record the switch model, port configuration, SB1000 firmware version, and LED state before contacting support.
- Confirm that the network provides 2.4 GHz 802.11 b/g/n service. SB1000 does not connect to a 5 GHz-only network.
- Test the unit outside the metal panel, or with the access point temporarily closer to the installation.
- Check the SSID, password, DHCP, gateway, and DNS settings.
- If both Ethernet and Wi-Fi are available, use Ethernet to determine whether the issue is limited to the radio connection.
Metal enclosures can attenuate the built-in radio enough to make Wi-Fi unreliable. In that situation, use Ethernet or change the access-point or enclosure arrangement.
Capacity note: enabling Wi-Fi consumes device memory and can reduce the practical point capacity by approximately 300 points. This does not normally explain a failure to join the network, but it is relevant on heavily configured units.
- Ask the utility or power company whether communication on the meter’s HAN port is enabled. It is not always enabled by default and may be disabled after a change of building owner.
- Check that the HAN cable is fully inserted at both the meter and HAN2X.
- Compare the meter information shown on the HAN2X Home page with the values available on the meter display.
If the utility confirms that the HAN port is active and the HAN LED remains off, include the meter manufacturer and model when contacting Varibits support.
Many AMS meters send accumulated energy data only once per hour, even though power and other values update more frequently.
- Leave HAN2X connected across at least one full-hour boundary.
- Confirm that other live meter values continue to update.
- If energy values are still missing after more than one hour, send a debug report from the HAN2X Help page. The device report contains information that is not available to the public WordPress site.
Compare the HAN2X values with the phase information available directly on the AMS meter display.
- A single-phase meter normally reports values only for L1.
- Some installations or meter configurations do not monitor every phase.
- HAN2X cannot create phase values that the meter does not transmit.
If the meter display shows a phase that is consistently missing from HAN2X, send a debug report from the HAN2X Help page and include the meter manufacturer and model.
If HAN2X agrees with the AMS meter display but the values are lower than expected for the installation, the meter may be measuring only a fraction of the primary current through current transformers.
- Ask the utility or installer for the current-transformer ratio or scale factor used for the meter.
- Enter the factor in the HAN2X Settings page.
- The same factor is available through Modbus registers 40049–40050. Check the current HAN2X manual for the datatype and write procedure before changing it over Modbus.
Do not guess the factor. An incorrect value makes all scaled energy, power, and current readings misleading.
If you can open the HAN2X web interface, the device is connected to the IP network. Continue with the Modbus-specific checks:
- Use the current HAN2X IP address and the Modbus TCP port configured under Settings. The default port is 502.
- Confirm that the client uses the configured Modbus unit or slave address.
- Check whether the client expects zero-based register offsets or 4xxxx reference numbers.
- As a basic read test, request meter power from holding registers 40001–40002. The value spans two 16-bit registers and is represented as a 32-bit integer; confirm byte and word order in the current manual.
If the test fails, record the exact request, unit address, exception or timeout, and HAN2X firmware version.
- Include the URI scheme in the broker address, for example
mqtt://192.168.1.200 or ws://broker.example.com.
- Confirm the port. Port 1883 is commonly used for unencrypted MQTT, but the configured broker may use another port.
- Check the username, password, and configured topic prefix.
- If the broker is specified by hostname, verify the HAN2X gateway and DNS settings.
- Check the firmware release notes before selecting an encrypted transport. The embedded Help in older HAN2X firmware states that encrypted MQTT is not supported.
When contacting support, include the broker URI with credentials removed, the port, the selected transport, and the HAN2X firmware version.
