All register values read as zero or NaN. What is wrong?

The UMG96RME returns float32 values across two consecutive 16-bit Modbus registers. If your gateway requests only one register per address instead of two (length 2), the value will be malformed or zero. Confirm that the template requests 2 registers for every float32 entry starting at the base address.

Current readings look correct on the meter display but are wrong over Modbus.

Float32 registers on the UMG96RME already incorporate the programmed current transformer ratio. If the CT ratio has not been set correctly on the device (Addr. parameter menu), the Modbus value will be scaled incorrectly. Verify the CT primary and secondary values in the device parameter menu match your installed transformers.

The gateway cannot communicate with the meter at all. How do I diagnose?

Check that the RS485 bus address configured on the UMG96RME matches the unit ID in the ModbusCloud portal. Also verify baud rate, data bits (8), parity (none), and stop bits (2) on both sides. Ensure the cable is shielded twisted-pair; CAT-style cables are not suitable for RS485 on this device.

Energy counter values are unexpectedly low or appear to have reset.

The UMG96RME provides a reset-energy-meter function via parameter address 507, accessible over Modbus. If another system or user accidentally triggered this parameter, the counters will have cleared. Restrict Modbus write access to the device to authorised systems only to prevent unintended counter resets.

Free Modbus template: Janitza UMG96RME

Name: Janitza UMG96RME
Brand: Janitza
SKU: f8682016-53d8-48fd-a268-56cd8bfd5331

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Free Modbus template: Janitza UMG96RME | ModbusCloud

Registers (18)

18 read / 0 write

Name	Address	Function	Type	Unit	Access
voltage_l1 Phase L1 to neutral RMS voltage, in volts.	19000	FC03	float32	V	R
voltage_l2 Phase L2 to neutral RMS voltage, in volts.	19002	FC03	float32	V	R
voltage_l3 Phase L3 to neutral RMS voltage, in volts.	19004	FC03	float32	V	R
current_l1 RMS current on phase L1, in amperes.	19012	FC03	float32	A	R
current_l2 RMS current on phase L2, in amperes.	19014	FC03	float32	A	R
current_l3 RMS current on phase L3, in amperes.	19016	FC03	float32	A	R
current Total three-phase RMS current sum, in amperes.	19018	FC03	float32	A	R
active_power_l1 Active real power on phase L1, in watts.	19020	FC03	float32	W	R
active_power_l2 Active real power on phase L2, in watts.	19022	FC03	float32	W	R
active_power_l3 Active real power on phase L3, in watts.	19024	FC03	float32	W	R
active_power Total three-phase active power, in watts.	19026	FC03	float32	W	R
reactive_power_l1 Reactive power on phase L1, in volt-amperes reactive.	19036	FC03	float32	W	R
reactive_power_l2 Reactive power on phase L2, in volt-amperes reactive.	19038	FC03	float32	W	R
reactive_power_l3 Reactive power on phase L3, in volt-amperes reactive.	19040	FC03	float32	W	R
reactive_power Total three-phase reactive power, in var.	19042	FC03	float32	var	R
frequency Mains supply frequency, in hertz.	19050	FC03	float32	Hz	R
active_consumption_energy Cumulative active energy consumed from the grid, in watt-hours.	19068	FC03	float32	Wh	R
active_production_energy Cumulative active energy exported to the grid, in watt-hours.	19076	FC03	float32	Wh	R