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Power meter (power analyser) · Modbus register map
Janitza UMG 104 power analyser (RS-485 Modbus RTU) Modbus register map
Updated 29 October 2026
The UMG 104 is a power analyser with four voltage and four current inputs and RS-485 / RS-232 serial ports, acting as a Modbus slave. Values are big-endian 32-bit floats that already include the CT/VT ratios. This map covers the 19000-19120 'frequently required readings' block, the fourth channel, consumed/delivered energy totals, digital I/O, the RS-485 address and energy reset commands.
This page lists 69 Modbus registers for the Janitza UMG 104 power analyser (RS-485 Modbus RTU) — 5 writable — with the table, 0-based wire address, data type, word order, scale, units and access of each, re-typed from Janitza’s own free documentation (linked below) and checked against it.
- Manufacturer
- Janitza
- Model
- UMG 104 power analyser (RS-485 Modbus RTU)
- Equipment type
- Power meter (power analyser)
- Registers
- 69 (5 writable)
- Transport
- Modbus RTU
- Default unit ID
- Not stated
- Default serial
- 8N2
- Documented addressing
- 0-based (the number printed is the address on the wire)
- 32-bit word order
- ABCD high word first (big-endian)
- Firmware
- 1.268
- Also known as
- UMG104, UMG 104, Janitza UMG104
Integration notes: Janitza UMG 104 power analyser (RS-485 Modbus RTU)
Read holding registers (function 03) from 19000: the 122-register block gives volts, amps, power, CosPhi, frequency, energy and THD as big-endian floats. For all-tariff energy totals read 9851 (consumed) and 9863 (delivered).
Minimum registers to map
Addresses are 0-based wire addresses. Enough to monitor and run the unit; map more as the job needs.
| Register | Name | Type | Why | Access |
|---|---|---|---|---|
| HR 19000 | Voltage L1-N | FLOAT32 ABCD | Voltage L1-N | Read |
| HR 19012 | Current L1 | FLOAT32 ABCD | Current L1 | Read |
| HR 19026 | Real power total | FLOAT32 ABCD | Total real power | Read |
| HR 19034 | Apparent power total | FLOAT32 ABCD | Total apparent power | Read |
| HR 19050 | Frequency | FLOAT32 ABCD | Frequency | Read |
| HR 9851 | Real energy L1-L3, consumed | FLOAT32 ABCD | Consumed real energy, all tariffs | Read |
| HR 9863 | Real energy L1-L3, delivered | FLOAT32 ABCD | Delivered real energy, all tariffs | Read |
Enable Modbus control & writes
The list holds the RS-485 Modbus device address at 10180 (read/write). It gives no menu path or other enable step.
Byte order & addressing
- Addresses are used as printed (0-based).
- Floats are ABCD; add 32768 to an address to get the same value little-endian.
- Energy is in Wh and varh, not kWh.
- Rotation field (19052) is a float: 1, 0 or -1.
Network setup
- Use 8 data bits and no parity; the device transmits 2 stop bits (the master may use 1 or 2).
- Set the CT/VT ratios at the device so the float values read in primary units.
- Write 1 to 9997 / 9998 to clear the real / reactive energy counters.
Watch out for
- 19068 is tariff 1 only; use 9851 for the consumed total.
- Short-format copies elsewhere in the list ignore the CT/VT ratio.
Janitza UMG 104 power analyser (RS-485 Modbus RTU) Modbus registers
Address = 0-based wire address (the documented number is shown under it when it differs) · Order: ABCD = high word first, CDAB = low word first · Scale: engineering value = raw × scale.
| Table | Address | Name | Description | Type | Order | Scale | Units | Access | Values / bits |
|---|---|---|---|---|---|---|---|---|---|
| HR | 1323 | Voltage L4-N | Fourth voltage input. | FLOAT32 | ABCD | V | Read | ||
| HR | 1331 | Current L4 | Fourth current input. | FLOAT32 | ABCD | A | Read | ||
| HR | 1339 | Real power L4 | FLOAT32 | ABCD | W | Read | |||
| HR | 1365 | Current sum L1-L4 (vector) | Vector sum of all four current inputs. | FLOAT32 | ABCD | A | Read | ||
| HR | 1377 | Real power L1-L4 | Sum of all four channels. | FLOAT32 | ABCD | W | Read | ||
| HR | 1447 | Voltage unbalance | FLOAT32 | ABCD | % | Read | |||
| HR | 1461 | Internal temperature | FLOAT32 | ABCD | °C | Read | |||
| HR | 9851 | Real energy L1-L3, consumed | Total over all tariffs. | FLOAT32 | ABCD | Wh | Read | ||
| HR | 9853 | Real energy L1-L4, consumed | FLOAT32 | ABCD | Wh | Read | |||
| HR | 9863 | Real energy L1-L3, delivered | Total over all tariffs. | FLOAT32 | ABCD | Wh | Read | ||
| HR | 9865 | Real energy L1-L4, delivered | FLOAT32 | ABCD | Wh | Read | |||
| HR | 9875 | Real energy L1-L3, consumed, HT (rate 1) | Tariff 1, high rate. | FLOAT32 | ABCD | Wh | Read | ||
| HR | 9887 | Real energy L1-L3, consumed, NT (rate 2) | Tariff 1, low rate. | FLOAT32 | ABCD | Wh | Read | ||
| HR | 9973 | Digital output 1 status | INT16 | Read/write | 0 = Not active; 1 = Active | ||||
| HR | 9974 | Digital output 2 status | INT16 | Read/write | 0 = Not active; 1 = Active | ||||
| HR | 9975 | Digital input 1 status | INT16 | Read | 0 = Not active; 1 = Active | ||||
| HR | 9976 | Digital input 2 status | INT16 | Read | 0 = Not active; 1 = Active | ||||
| HR | 9997 | Delete real energy counters | Write 1 to clear all real energy counters. | INT16 | Read/write | ||||
| HR | 9998 | Delete reactive energy counters | Write 1 to clear all reactive energy counters. | INT16 | Read/write | ||||
| HR | 10176 | Serial number | UINT32 | ABCD | Read | ||||
| HR | 10180 | RS-485 Modbus address | Device address on the RS-485 bus. | INT32 | ABCD | Read/write | |||
| HR | 19000 | Voltage L1-N | FLOAT32 | ABCD | V | Read | |||
| HR | 19002 | Voltage L2-N | FLOAT32 | ABCD | V | Read | |||
| HR | 19004 | Voltage L3-N | FLOAT32 | ABCD | V | Read | |||
| HR | 19006 | Voltage L1-L2 | FLOAT32 | ABCD | V | Read | |||
| HR | 19008 | Voltage L2-L3 | FLOAT32 | ABCD | V | Read | |||
| HR | 19010 | Voltage L3-L1 | FLOAT32 | ABCD | V | Read | |||
| HR | 19012 | Current L1 | FLOAT32 | ABCD | A | Read | |||
| HR | 19014 | Current L2 | FLOAT32 | ABCD | A | Read | |||
| HR | 19016 | Current L3 | FLOAT32 | ABCD | A | Read | |||
| HR | 19018 | Neutral current (vector sum) | Calculated vector sum of the three phase currents. | FLOAT32 | ABCD | A | Read | ||
| HR | 19020 | Real power L1 | FLOAT32 | ABCD | W | Read | |||
| HR | 19022 | Real power L2 | FLOAT32 | ABCD | W | Read | |||
| HR | 19024 | Real power L3 | FLOAT32 | ABCD | W | Read | |||
| HR | 19026 | Real power total | Sum of L1-L3. | FLOAT32 | ABCD | W | Read | ||
| HR | 19028 | Apparent power L1 | FLOAT32 | ABCD | VA | Read | |||
| HR | 19030 | Apparent power L2 | FLOAT32 | ABCD | VA | Read | |||
| HR | 19032 | Apparent power L3 | FLOAT32 | ABCD | VA | Read | |||
| HR | 19034 | Apparent power total | Sum of L1-L3. | FLOAT32 | ABCD | VA | Read | ||
| HR | 19036 | Reactive power L1 (fundamental) | FLOAT32 | ABCD | var | Read | |||
| HR | 19038 | Reactive power L2 (fundamental) | FLOAT32 | ABCD | var | Read | |||
| HR | 19040 | Reactive power L3 (fundamental) | FLOAT32 | ABCD | var | Read | |||
| HR | 19042 | Reactive power total (fundamental) | Sum of L1-L3. | FLOAT32 | ABCD | var | Read | ||
| HR | 19044 | CosPhi L1 (fundamental) | FLOAT32 | ABCD | Read | ||||
| HR | 19046 | CosPhi L2 (fundamental) | FLOAT32 | ABCD | Read | ||||
| HR | 19048 | CosPhi L3 (fundamental) | FLOAT32 | ABCD | Read | ||||
| HR | 19050 | Frequency | FLOAT32 | ABCD | Hz | Read | |||
| HR | 19052 | Rotation field | Float: 1 = clockwise, 0 = none, -1 = anticlockwise. | FLOAT32 | ABCD | Read | |||
| HR | 19054 | Real energy L1 | FLOAT32 | ABCD | Wh | Read | |||
| HR | 19056 | Real energy L2 | FLOAT32 | ABCD | Wh | Read | |||
| HR | 19058 | Real energy L3 | FLOAT32 | ABCD | Wh | Read | |||
| HR | 19060 | Real energy L1-L3 | Three-phase total, not split into consumed and delivered. | FLOAT32 | ABCD | Wh | Read | ||
| HR | 19062 | Real energy L1, consumed | FLOAT32 | ABCD | Wh | Read | |||
| HR | 19064 | Real energy L2, consumed | FLOAT32 | ABCD | Wh | Read | |||
| HR | 19066 | Real energy L3, consumed | FLOAT32 | ABCD | Wh | Read | |||
| HR | 19070 | Real energy L1, delivered | FLOAT32 | ABCD | Wh | Read | |||
| HR | 19072 | Real energy L2, delivered | FLOAT32 | ABCD | Wh | Read | |||
| HR | 19074 | Real energy L3, delivered | FLOAT32 | ABCD | Wh | Read | |||
| HR | 19076 | Real energy L1-L3, delivered | FLOAT32 | ABCD | Wh | Read | |||
| HR | 19084 | Apparent energy L1-L3 | FLOAT32 | ABCD | VAh | Read | |||
| HR | 19092 | Reactive energy L1-L3 | FLOAT32 | ABCD | varh | Read | |||
| HR | 19100 | Reactive energy inductive L1-L3 | FLOAT32 | ABCD | varh | Read | |||
| HR | 19108 | Reactive energy capacitive L1-L3 | FLOAT32 | ABCD | varh | Read | |||
| HR | 19110 | THD voltage L1-N | FLOAT32 | ABCD | % | Read | |||
| HR | 19112 | THD voltage L2-N | FLOAT32 | ABCD | % | Read | |||
| HR | 19114 | THD voltage L3-N | FLOAT32 | ABCD | % | Read | |||
| HR | 19116 | THD current L1 | FLOAT32 | ABCD | % | Read | |||
| HR | 19118 | THD current L2 | FLOAT32 | ABCD | % | Read | |||
| HR | 19120 | THD current L3 | FLOAT32 | ABCD | % | Read |
Notes on this map
- Byte order: the list says its addresses return data big-endian (high byte first, high word in the lower register = ABCD). Adding 32768 to an address returns the same value little-endian; that mirror block is not listed.
- Data types in the list: short = signed 16-bit, int = signed 32-bit, uint = unsigned 32-bit, float = IEEE 754 32-bit. Float and integer values include the CT/VT ratios; short values do not.
- 19068 in the frequently-read block is the consumed energy of tariff 1 (rate 1) only, so it is left out; the all-tariff consumed and delivered totals are taken from the energy table (9851 / 9863).
- Transfer parameters (p. 5): 9600-115200 baud, 8 data bits, no parity, the UMG 104 sends 2 stop bits. The list does not give a default baud rate or device address.
- Left out: RS-485 mode and baud rate (10182 / 10184), RS-232 settings and IP settings, because the list gives no value coding for them; the summed power factor at 1373, whose formula is printed as Psum3/Qsum3 (likely a typo); the SHORT copies of values; harmonics, min/max/mean blocks, monthly energy, tariffs 3/4 and comparators.
- Left out: the CT/VT ratio rows 10032-10062. They are four-element arrays and every element is labelled 'L1, L2, L3', so which element belongs to which input is not clear from the list.
Check it against the live device. A register map tells you what the controller can expose; the unit in front of you may differ by firmware or options. Read a few registers and compare them with the unit’s own display; for a 32-bit value the float and byte-order decoder shows all four word orders at once, so a wrong word order or scale is obvious. New to this? Read what a register map is and why addresses are off by one.
Questions about the Janitza UMG 104 power analyser (RS-485 Modbus RTU)
What Modbus registers does the Janitza UMG 104 power analyser (RS-485 Modbus RTU) have?
This map lists 69 registers: 69 holding registers. 5 of them can be written. Registers vary with firmware, options and configuration, so confirm against the device.
Are the Janitza UMG 104 power analyser (RS-485 Modbus RTU) Modbus addresses 0-based or 1-based?
The manufacturer's document numbers registers 0-based (the number printed is the address on the wire). Every address on this page is the 0-based wire address you put in the request; the documented number is shown under it where it differs. Addresses are printed as the protocol address and sent unchanged: 19000 is requested as 19000. The list starts at address 0 (real-time clock), which only fits 0-based numbering. In a 1-based or Modicon tool enter 19001 / 419001.
What byte order does the Janitza UMG 104 power analyser (RS-485 Modbus RTU) use for 32-bit values?
Multi-register values in this map use ABCD (high word first (big-endian)). Set your client to this order for every 32/64-bit value in the table.
What are the minimum Modbus registers to integrate the Janitza UMG 104 power analyser (RS-485 Modbus RTU)?
Start with HR 19000 Voltage L1-N (Voltage L1-N); HR 19012 Current L1 (Current L1); HR 19026 Real power total (Total real power); HR 19034 Apparent power total (Total apparent power); HR 19050 Frequency (Frequency); HR 9851 Real energy L1-L3, consumed (Consumed real energy, all tariffs); HR 9863 Real energy L1-L3, delivered (Delivered real energy, all tariffs).
How do I enable Modbus control of the Janitza UMG 104 power analyser (RS-485 Modbus RTU)?
The list holds the RS-485 Modbus device address at 10180 (read/write). It gives no menu path or other enable step.
Where is the official Janitza UMG 104 power analyser (RS-485 Modbus RTU) Modbus documentation?
The source is Power Analyser UMG 104 - Modbus-address list and Formulary (Firmware 1.268) (1.041.006.1.e), revision 2023-01, published free by Janitza at https://www.janitza.com/files/download/manuals/current/UMG104/janitza-mal-umg104-en.pdf.
More Janitza Modbus register maps
- Power meter (power quality analyser)
Janitza UMG 509-PRO power quality analyser (Modbus RTU / Modbus TCP)
UMG 509-PRO per Modbus address list 1.059.004.2.n (06/2024).
Also known as: UMG509-PRO, UMG 509PRO, UMG509PRO, Janitza UMG 509 - Power meter (power quality analyser)
Janitza UMG 512-PRO power quality analyser (Modbus RTU / Modbus TCP)
UMG 512-PRO power quality analyser, per address list 1.054.016.3.k (08/2023).
Also known as: UMG512-PRO, UMG 512, UMG512, UMG 512 PRO, Janitza UMG512-PRO - Power meter (power quality analyser)
Janitza UMG 604-PRO power analyser (Modbus RTU / Modbus TCP)
UMG 604-PRO from firmware release 5.028, per address list 1.033.034.e (08/2023).
Also known as: UMG604-PRO, UMG 604PRO, UMG604PRO, UMG 604-EP PRO, Janitza UMG 604 - Power meter (power quality analyser)
Janitza UMG 605-PRO power quality analyser (Modbus RTU / Modbus TCP)
UMG 605-PRO from firmware release 5.028, per address list 1.038.009.7.h (09/2022).
Also known as: UMG605-PRO, UMG 605PRO, UMG605PRO, Janitza UMG 605 - Power meter (energy analyser)
Janitza UMG 96-S2 energy analyser (serial Modbus)
UMG 96-S2 energy analyser, per address list 2.062.026.1.b (10/2019).
Also known as: UMG96-S2, UMG 96 S2, UMG96S2, Janitza UMG96-S2 - Power meter (power analyser)
Janitza UMG 96RM power analyser (basic device, RS-485 Modbus RTU)
UMG 96RM basic device from firmware release 1.14, per address list 1.040.034.t; the same list covers the shared registers of the -P, -CBM and -PN extensions. Other UMG 96RM variants (e.g. the Ethernet -E / -EL) are not covered by this list.
Also known as: UMG96RM, UMG 96 RM, UMG 96RM-P, UMG 96RM-CBM, UMG 96RM-PN, Janitza UMG96RM - Power meter (power analyser)
Janitza UMG 96RM-E power analyser (Ethernet, Modbus TCP / RTU)
UMG 96RM-E from firmware 3.01 / hardware release 104, per address list 1.040.085.8.n (06/2024).
Also known as: UMG96RM-E, UMG 96 RM-E, UMG96RME, Janitza UMG96RM-E
Source: Power Analyser UMG 104 - Modbus-address list and Formulary (Firmware 1.268) · 1.041.006.1.e · rev. 2023-01. Register numbers, types, scaling and units are reproduced as published; descriptions are our own.