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Janitza UMG 103-CBM Modbus register map

Also searched as: UMG103-CBM

53 Modbus registers of the Janitza UMG 103-CBM, with the address on the wire, the 30001-style reference, data type, byte order, unit and scale. Transcribed from UMG 103-CBM Firmware version 2.0 and higher: Modbus-address list and formulary (07/2025).

Janitza UMG 103-CBM DIN-rail energy meter with RS485 (firmware 2.0 and later); 32-bit float readings.

Registers Read it by name
Device type
Energy meter
Registers
53
Interfaces
Modbus RTU
Byte order (multi-register values)
ABCD
Serial settings
8 data bits, no parity, 2 stop bits; 9600 to 115200 baud

Hardware verification

Not yet verified on hardware. The map is transcribed from the vendor document and checked against it by script; check the first readings against the device display.

Verify it on your device What the levels mean

Connection notes

  • Addresses are the list's register numbers, sent unchanged: Janitza's UMG address lists number from register 0 and give no example frame.
  • Only the float block of frequently required readings (19000-19120) is transcribed; the list repeats many of these values at other addresses, as floats and as scaled shorts.
  • Function 03 and 04 both read these registers; floats are big-endian (ABCD). The list says adding 32768 to an address returns the same value little-endian.
  • Float and integer values include the configured current and voltage transformer ratios.
  • Left out 19054-19060 and 19086-19092: on this device the list maps them to the same values as 19062-19068 and 19094-19100 and marks them as differing from the standard UMG assignment.

Registers

Grouped as in the vendor document.

Voltage 6 registers
Name and key Reference Address Type Byte order Unit Scale
Voltage L1-Nvoltage_l1_n 419001 0x4A38 float32 ABCD V
Voltage L2-Nvoltage_l2_n 419003 0x4A3A float32 ABCD V
Voltage L3-Nvoltage_l3_n 419005 0x4A3C float32 ABCD V
Voltage L1-L2voltage_l1_l2 419007 0x4A3E float32 ABCD V
Voltage L2-L3voltage_l2_l3 419009 0x4A40 float32 ABCD V
Voltage L3-L1voltage_l3_l1 419011 0x4A42 float32 ABCD V
Current 4 registers
Name and key Reference Address Type Byte order Unit Scale
Apparent current, L1current_l1 419013 0x4A44 float32 ABCD A
Apparent current, L2current_l2 419015 0x4A46 float32 ABCD A
Apparent current, L3current_l3 419017 0x4A48 float32 ABCD A
Vector sum; IN=I1+I2+I3current_vector_sum 419019 0x4A4A float32 ABCD A
Power 12 registers
Name and key Reference Address Type Byte order Unit Scale
Real power L1active_power_l1 419021 0x4A4C float32 ABCD W
Real power L2active_power_l2 419023 0x4A4E float32 ABCD W
Real power L3active_power_l3 419025 0x4A50 float32 ABCD W
Sum; Psum3=P1+P2+P3active_power_total 419027 0x4A52 float32 ABCD W
Apparent power L1apparent_power_l1 419029 0x4A54 float32 ABCD VA
Apparent power L2apparent_power_l2 419031 0x4A56 float32 ABCD VA
Apparent power L3apparent_power_l3 419033 0x4A58 float32 ABCD VA
Sum; Ssum3=S1+S2+S3apparent_power_total 419035 0x4A5A float32 ABCD VA
Reactive power (mains frequ.) L1reactive_power_l1 419037 0x4A5C float32 ABCD var
Reactive power (mains frequ.) L2reactive_power_l2 419039 0x4A5E float32 ABCD var
Reactive power (mains frequ.) L3reactive_power_l3 419041 0x4A60 float32 ABCD var
Sum; Qsum3=Q1+Q2+Q3reactive_power_total 419043 0x4A62 float32 ABCD var
Frequency 1 registers
Name and key Reference Address Type Byte order Unit Scale
Measured frequencyfrequency 419051 0x4A6A float32 ABCD Hz
Energy 20 registers
Name and key Reference Address Type Byte order Unit Scale
Real energy L1, consumedactive_energy_consumed_l1 419063 0x4A76 float32 ABCD Wh
Real energy L2, consumedactive_energy_consumed_l2 419065 0x4A78 float32 ABCD Wh
Real energy L3, consumedactive_energy_consumed_l3 419067 0x4A7A float32 ABCD Wh
Real energy L1..L3, consumed, rate 1active_energy_consumed_total_rate_1 419069 0x4A7C float32 ABCD Wh
Real energy L1, deliveredactive_energy_delivered_l1 419071 0x4A7E float32 ABCD Wh
Real energy L2, deliveredactive_energy_delivered_l2 419073 0x4A80 float32 ABCD Wh
Real energy L3, deliveredactive_energy_delivered_l3 419075 0x4A82 float32 ABCD Wh
Real energy L1..L3, deliveredactive_energy_delivered_total 419077 0x4A84 float32 ABCD Wh
Apparent energy L1apparent_energy_l1 419079 0x4A86 float32 ABCD VAh
Apparent energy L2apparent_energy_l2 419081 0x4A88 float32 ABCD VAh
Apparent energy L3apparent_energy_l3 419083 0x4A8A float32 ABCD VAh
Apparent energy L1..L3apparent_energy_total 419085 0x4A8C float32 ABCD VAh
Reactive energy, inductive, L1reactive_energy_inductive_l1 419095 0x4A96 float32 ABCD varh
Reactive energy, inductive, L2reactive_energy_inductive_l2 419097 0x4A98 float32 ABCD varh
Reactive energy, inductive, L3reactive_energy_inductive_l3 419099 0x4A9A float32 ABCD varh
Reactive energy L1..L3, ind.reactive_energy_inductive_total 419101 0x4A9C float32 ABCD varh
Reactive energy, capacitive, L1reactive_energy_capacitive_l1 419103 0x4A9E float32 ABCD varh
Reactive energy, capacitive, L2reactive_energy_capacitive_l2 419105 0x4AA0 float32 ABCD varh
Reactive energy, capacitive, L3reactive_energy_capacitive_l3 419107 0x4AA2 float32 ABCD varh
Reactive energy L1..L3, cap.reactive_energy_capacitive_total 419109 0x4AA4 float32 ABCD varh
Status 1 registers
Name and key Reference Address Type Byte order Unit Scale
Rotation field; 1=right, 0=none, -1=leftrotation_field 419053 0x4A6C float32 ABCD
Power factor 3 registers
Name and key Reference Address Type Byte order Unit Scale
Fund.power factor, CosPhi; UL1 IL1cos_phi_l1 419045 0x4A64 float32 ABCD
Fund.power factor, CosPhi; UL2 IL2cos_phi_l2 419047 0x4A66 float32 ABCD
Fund.power factor, CosPhi; UL3 IL3cos_phi_l3 419049 0x4A68 float32 ABCD
Harmonics 6 registers
Name and key Reference Address Type Byte order Unit Scale
Harmonic, THD,U L1-Nthd_voltage_l1_n 419111 0x4AA6 float32 ABCD %
Harmonic, THD,U L2-Nthd_voltage_l2_n 419113 0x4AA8 float32 ABCD %
Harmonic, THD,U L3-Nthd_voltage_l3_n 419115 0x4AAA float32 ABCD %
Harmonic, THD,I L1thd_current_l1 419117 0x4AAC float32 ABCD %
Harmonic, THD,I L2thd_current_l2 419119 0x4AAE float32 ABCD %
Harmonic, THD,I L3thd_current_l3 419121 0x4AB0 float32 ABCD %

Source documents

View this map on GitHub (YAML)

Read it by name

Read the UMG 103-CBM with an AI assistant

The Proxus Industrial MCP Server includes this map. Set it on the device, and Claude, Cursor or VS Code reads registers by key with the right type, byte order, scale and unit. It only reads.

This device speaks Modbus RTU: reach it through a Modbus TCP gateway and use the gateway’s address with the device’s unit ID.

Get the MCP server

proxus-mcp.json

{
  "devices": {
    "umg-1": {
      "protocol": "modbus-tcp",
      "host": "192.168.10.40",
      "unit_id": 1,
      "map": "janitza/umg-103-cbm"
    }
  }
}

Ask your assistant

Read voltage_l1_n, voltage_l2_n, voltage_l3_n from umg-1.

The tool call it makes

read_named(device: "umg-1", keys: ["voltage_l1_n", "voltage_l2_n", "voltage_l3_n"])

Have this device? Verify the map.

Ask your assistant to run verify_device_map. It reads every register once, read-only, checks that the values are plausible and asks you to compare two values with the display. You get a report and a prefilled GitHub issue to submit; your name goes on this map’s verified list.

How verification works

Collecting from many devices?

Proxus reads Modbus TCP and RTU devices next to the machines, keeps the history and delivers the values to dashboards, databases and AI.

Modbus in Proxus Industrial connectivity

Data: Modbus Register Maps by Proxus contributors, CC BY 4.0.