The gateway connects but all register values show zero or null. Why?

Modbus TCP is disabled by default on the MG100. Open the ATMOZEN app or the device's local web interface, navigate to the communication or Modbus section, and explicitly enable Modbus TCP. The device must also have an active grid connection before meter registers report live values.

Phase current values look incorrect or implausibly large. What should I check?

Current registers (addresses 60090, 60092, 60094) are int16 signed values. If your Modbus master is interpreting them as unsigned uint16, negative currents (grid export) will appear as very large positive numbers. Confirm your client treats these registers as signed 16-bit integers.

The energy register (address 60184) never increments. What is wrong?

The energy register is a uint64 spanning four consecutive 16-bit holding registers. Some Modbus clients default to reading only two registers for a 32-bit value. Verify your client is configured to read four registers starting at address 60184, and that byte and word order match the MG100 protocol specification (big-endian by default for TCP devices).

I get timeout errors even though the MG100 IP address is reachable. What now?

The MG100 supports multiple simultaneous communication channels (Wi-Fi, Ethernet, PLC, RS485). If the device is under heavy load from the ATMOZEN cloud connection or PLC traffic, Modbus TCP responses can be delayed. Increase the Modbus response timeout in the ModbusCloud portal to at least 2000 ms, and ensure no firewall rule is blocking TCP port 502 on the local network.

Free Modbus template: Atmoce MG100 M-gateway (grid)

Name: Atmoce MG100 M-gateway (grid)
Brand: Atmoce
SKU: afdca684-22d9-4efc-b93e-ca5e3f0d0421

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Free Modbus template: Atmoce MG100 M-gateway (grid) | ModbusCloud

Registers (8)

8 read / 0 write

Name	Address	Function	Type	Unit	Access
power Total active power at the grid connection point, signed integer, watts.	60073	FC03	int32	W	R
energy Cumulative active energy measured at the grid connection point.	60184	FC03	uint64		R
currents_a Phase A current at the grid connection point, signed, amperes.	60090	FC03	int16	A	R
currents_b Phase B current at the grid connection point, signed, amperes.	60092	FC03	int16	A	R
currents_c Phase C current at the grid connection point, signed, amperes.	60094	FC03	int16	A	R
voltages_a Phase A voltage at the grid connection point, unsigned, volts.	60089	FC03	uint16	V	R
voltages_b Phase B voltage at the grid connection point, unsigned, volts.	60091	FC03	uint16	V	R
voltages_c Phase C voltage at the grid connection point, unsigned, volts.	60093	FC03	uint16	V	R