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Power meter (power quality analyser) · Modbus register map
Janitza UMG 604-PRO power analyser (Modbus RTU / Modbus TCP) Modbus register map
Updated 28 October 2026
The UMG 604-PRO is Janitza's DIN-rail power quality analyser with Ethernet and RS-485. It serves its measurements as big-endian 32-bit floats; the 'frequently required readings' block at 19000-19120 holds volts, amps, power, CosPhi, frequency, energy and THD and is the same block other Janitza meters use. This map covers that block plus the fourth channel, consumed energy total, digital I/O, energy resets, transformer settings and identity/network values.
This page lists 76 Modbus registers for the Janitza UMG 604-PRO power analyser (Modbus RTU / Modbus TCP) — 4 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 604-PRO power analyser (Modbus RTU / Modbus TCP)
- Equipment type
- Power meter (power quality analyser)
- Registers
- 76 (4 writable)
- Transport
- Modbus RTU, Modbus TCP
- Default unit ID
- 1
- Default serial
- 115200 baud, 8N2
- TCP port
- 502
- Documented addressing
- 0-based (the number printed is the address on the wire)
- 32-bit word order
- ABCD high word first (big-endian)
- Firmware
- Release 5.028 and higher
- Also known as
- UMG604-PRO, UMG 604PRO, UMG604PRO, UMG 604-EP PRO, Janitza UMG 604
Integration notes: Janitza UMG 604-PRO power analyser (Modbus RTU / Modbus TCP)
Read holding registers (function 03) from 19000: 60 registers give volts, amps, power, CosPhi, frequency and per-phase energy as big-endian floats; 19060-19077 adds the three-phase and delivered energy totals in Wh. Over Ethernet use Modbus TCP; over RS-485 use RTU at the device's address.
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 L1-L3 | FLOAT32 ABCD | Total real power | Read |
| HR 19034 | Apparent power total L1-L3 | FLOAT32 ABCD | Total apparent power | Read |
| HR 1373 | Power factor total L1-L3 | FLOAT32 ABCD | Total power factor | Read |
| HR 19050 | Frequency | FLOAT32 ABCD | Frequency | Read |
| HR 9851 | Real energy L1-L3, consumed | FLOAT32 ABCD | Consumed energy total | Read |
| HR 19076 | Real energy L1-L3, delivered | FLOAT32 ABCD | Delivered energy total | Read |
Enable Modbus control & writes
The 604-PRO answers Modbus on Ethernet and, as a slave, on RS-485. Set the Modbus address, baud rate and IP settings on the device or in GridVis (see the device manual).
Byte order & addressing
- Addresses are used as printed (0-based).
- Floats are ABCD (high word first). Add 32768 to an address for little-endian.
- Energy is in Wh and varh, not kWh.
- Rotation field (19052) is a float: 1, 0 or -1.
Network setup
- RS-485: 8 data bits, no parity, 2 stop bits on the device's own port; baud 9.6, 19.2, 38.4, 57.6, 115.2 or 921.6 kbps.
- Set CT/VT ratios first so the floats read in primary units.
- Writing 1 to 9997 clears real/apparent energy; 9998 clears reactive energy.
Watch out for
- The 'rate 1' consumed row in the 19000 block (19068) is tariff 1 only; use 9851 for the full consumed total.
- Short-format values elsewhere in the list skip the transformer ratios; do not mix them with the float values.
Janitza UMG 604-PRO power analyser (Modbus RTU / Modbus TCP) 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 (e.g. N-PE). | FLOAT32 | ABCD | V | Read | ||
| HR | 1331 | Current L4 | Fourth current input (measured neutral or extra feeder). | FLOAT32 | ABCD | A | Read | ||
| HR | 1373 | Power factor total L1-L3 | P sum / sqrt(P sum^2 + Q sum^2) over L1-L3. | FLOAT32 | ABCD | Read | |||
| HR | 1461 | Temperature input | Value of the external temperature sensor input. | FLOAT32 | ABCD | °C | Read | ||
| HR | 9827 | Real energy L1-L3 (9827 block) | Same total as 19060, from the main energy block. | FLOAT32 | ABCD | Wh | Read | ||
| HR | 9851 | Real energy L1-L3, consumed | Three-phase consumed (import) energy total. | FLOAT32 | ABCD | Wh | Read | ||
| HR | 9973 | Digital output 1 status | Marked read/write in the list. | INT16 | Read/write | ||||
| HR | 9974 | Digital output 2 status | Marked read/write in the list. | INT16 | Read/write | ||||
| HR | 9975 | Digital input 1 status | INT16 | Read | |||||
| HR | 9976 | Digital input 2 status | INT16 | Read | |||||
| HR | 9997 | Delete real and apparent energy | Write 1 to clear all real and apparent energy counters. | INT16 | Write | ||||
| HR | 9998 | Delete reactive energy | Write 1 to clear all reactive energy counters. | INT16 | Write | ||||
| HR | 10032 | CT primary L1 | Current transformer primary setting. | FLOAT32 | ABCD | A | Read | ||
| HR | 10034 | CT primary L2 | Current transformer primary setting. | FLOAT32 | ABCD | A | Read | ||
| HR | 10036 | CT primary L3 | Current transformer primary setting. | FLOAT32 | ABCD | A | Read | ||
| HR | 10040 | CT secondary L1 | Current transformer secondary setting. | FLOAT32 | ABCD | A | Read | ||
| HR | 10042 | CT secondary L2 | Current transformer secondary setting. | FLOAT32 | ABCD | A | Read | ||
| HR | 10044 | CT secondary L3 | Current transformer secondary setting. | FLOAT32 | ABCD | A | Read | ||
| HR | 10048 | VT primary L1 | Voltage transformer primary setting. | FLOAT32 | ABCD | V | Read | ||
| HR | 10056 | VT secondary L1 | Voltage transformer secondary setting. | FLOAT32 | ABCD | V | Read | ||
| HR | 10176 | Serial number | UINT32 | ABCD | Read | ||||
| HR | 10180 | Modbus address | RS-485 slave address. | INT32 | ABCD | Read | |||
| HR | 10190 | IP address | Packed 32-bit IPv4 address. | UINT32 | ABCD | Read | |||
| HR | 10192 | Subnet mask | Packed 32-bit IPv4 mask. | UINT32 | ABCD | Read | |||
| HR | 10194 | Gateway address | Packed 32-bit IPv4 gateway. | UINT32 | ABCD | Read | |||
| HR | 13437 | Firmware release | Text, 16 characters (8 registers). | STRING[16] | Read | ||||
| 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 L1-L3) | 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 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 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 L1-L3 (fundamental) | 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 (fundamental) | 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 | |||
| HR | 19636 | Average power factor | (PF1 + PF2 + PF3) / 3. | FLOAT32 | ABCD | Read | |||
| HR | 19716 | Transformer ratio lock | INT16 | Read | 0 = Not locked; 1 = Locked |
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, long64 = signed 64-bit.
- Float and integer values include the CT/VT ratios; short values do not. Only float and int/uint rows are used here, apart from the 16-bit status and command rows.
- Left out: 19068 (consumed L1-L3, tariff 1 only - not the consumed total). The consumed total is at 9851 (_WH_V[4]).
- Left out: harmonics, min/max/mean blocks, event and transient settings, logging, tariff 3/4 and month peaks, to keep the map short.
- Left out: baud rate (10184), RS-485 mode (10182) and DHCP mode (10196) because the list gives no value coding for them.
- The list has no read/write column. Only rows the list marks as writable (digital outputs 'r/w', delete commands '=1') are given write access here; CT/VT and network rows are listed read-only although they are device settings.
- String length: 10072 _DEV_NAME is printed as 64 and the next row starts 32 registers later, so string sizes are in characters; _RELEASE (16) is taken as 8 registers.
- Measured values refresh every 200 ms.
- Defaults and ports come from the UMG 604-PRO user manual (doc. 1.033.059.7.a, 02/2026, https://assets.janitza.com/ce18jq9ih0x6/15504e85f82efabc79f178/d1dfe38c6041322ca16c055682b88072/janitza-bhb-umg604pro-en.pdf): device address default 1, RS-485 baud default 115200 (setting 4), Modbus/TCP on port 502 and Modbus RTU over Ethernet on port 8000. The address list itself only gives the serial framing.
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 604-PRO power analyser (Modbus RTU / Modbus TCP)
What Modbus registers does the Janitza UMG 604-PRO power analyser (Modbus RTU / Modbus TCP) have?
This map lists 76 registers: 76 holding registers. 4 of them can be written. Registers vary with firmware, options and configuration, so confirm against the device.
Are the Janitza UMG 604-PRO power analyser (Modbus RTU / Modbus TCP) 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 (system time), which only fits a 0-based numbering. In a 1-based or Modicon tool enter 19001 / 419001.
What byte order does the Janitza UMG 604-PRO power analyser (Modbus RTU / Modbus TCP) 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 604-PRO power analyser (Modbus RTU / Modbus TCP)?
Start with HR 19000 Voltage L1-N (Voltage L1-N); HR 19012 Current L1 (Current L1); HR 19026 Real power total L1-L3 (Total real power); HR 19034 Apparent power total L1-L3 (Total apparent power); HR 1373 Power factor total L1-L3 (Total power factor); HR 19050 Frequency (Frequency); HR 9851 Real energy L1-L3, consumed (Consumed energy total); HR 19076 Real energy L1-L3, delivered (Delivered energy total).
How do I enable Modbus control of the Janitza UMG 604-PRO power analyser (Modbus RTU / Modbus TCP)?
The 604-PRO answers Modbus on Ethernet and, as a slave, on RS-485. Set the Modbus address, baud rate and IP settings on the device or in GridVis (see the device manual).
Where is the official Janitza UMG 604-PRO power analyser (Modbus RTU / Modbus TCP) Modbus documentation?
The source is Power Analyser UMG 604-PRO - Modbus-address and Formulary (firmware rel. 5.028 and higher) (1.033.034.e), revision 2023-08, published free by Janitza at https://www.janitza.com/files/download/manuals/current/UMG604-PRO/janitza-mal-umg604pro-en.pdf.
More Janitza Modbus register maps
- Power meter (power analyser)
Janitza UMG 104 power analyser (RS-485 Modbus RTU)
UMG 104 DIN-rail power analyser, firmware 1.268, per address list 1.041.006.1.e (01/2023).
Also known as: UMG104, UMG 104, Janitza UMG104 - 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 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 604-PRO - Modbus-address and Formulary (firmware rel. 5.028 and higher) · 1.033.034.e · rev. 2023-08. Register numbers, types, scaling and units are reproduced as published; descriptions are our own.