Janitza UMG 605-PRO

Power and energy meter

UMG 605-PRO monitors electrical measurements and power quality from a DIN-rail position. Its map for firmware 5.028 and higher gives a literal Float32 voltage read at address 19000. Commissioning must identify whether the RS-485 port is acting as a server, a master or part of a gateway arrangement, and confirm transformer ratios before values are accepted.

Janitza UMG 605-PRO
  • Modbus RTU

Power and energy meter

Compatibility

Documented read-only Modbus path

The UMG 605-PRO documentation defines an RS-485 Modbus server with FC03/FC04 measurement reads and a model-specific address list.

UMG 605-PRO using address-list document 1.038.009.7.h for firmware 5.028 and later as the starting map. Check the configured RS-485 role, then poll this instrument in Modbus server mode. Record CT/VT ratios and compare the first readings with the display. Earlier UMG 605 and UMG 604-PRO have separate model documents.

Connect it with

For the documented RS-485 Modbus RTU server interface

  • Modbus
  • Edge
  • Platforms
Power and energy meter
Interface
Gateway
Edge
Output
UMG 605-PROMeter RS-485 terminals
Isolated serial interfaceApproved RS-485-to-host adapter
ZGW-20 GatewayHosts Edge locally
EpiSensor EdgeEdge Modbus client
Customer platformMQTT · API · files
Modbus RTU · RS-485
Isolated serial
Runs locally
Optional onward data
Set the instrument to its documented server role for reading its own measurements. Do not assume an installed master or transparent-gateway configuration can be polled unchanged. The customer-platform output is optional; Edge remains the local system of record.

Models

Download
ModelsInterfaceRoute into Edge
UMG 605-PRO, firmware 5.028+RS-485 and Ethernet, with documented Modbus server functionsThis guide uses the instrument’s own RS-485 server readings.
UMG 604-PRO and earlier UMG 605Different model and documentation revisionUse their separate maps; do not copy this firmware-scoped address list.

Interface

Documented measurements and integration boundaries for UMG 605-PRO.

  • L1-N voltage as Float32 in V at decimal address 19000.
  • Current, power and energy float readings with configured transformer factors.
  • Harmonics and power-quality values in separate map groups.
  • Historic event and transient records outside the simple instantaneous Modbus check.

Assessment

UMG 605-PRO using address-list document 1.038.009.7.h for firmware 5.028 and later as the starting map. Check the configured RS-485 role, then poll this instrument in Modbus server mode. Record CT/VT ratios and compare the first readings with the display. Earlier UMG 605 and UMG 604-PRO have separate model documents.

InteroperabilityWell supported
The model-specific map defines FC03/FC04 server reads, literal addresses, format and serial parameters.1
AccuracySupported with conditions
The device supports Class S power-quality analysis and CT-based measurements, with configured transformer factors included in float readings.13
SecurityNot yet assessed
The retained manual does not establish authenticated or encrypted Modbus for this read path.2
ReliabilitySupported with conditions
A local analyser and 200 ms address-list update rate support comparison, but historic events require their own retrieval.12
RuggednessSupported with conditions
The manual defines indoor mounting and supply limits for the exact equipment; verify the cabinet conditions.2
ScalabilitySupported with conditions
RS-485 server addressing can be designed for multiple devices; bus limits and poll rate remain installation-specific.12
LifecycleNot yet assessed
The retained map establishes firmware applicability but not a future support term.1

Setup

Read the present L1-N voltage

The firmware-scoped UMG 605-PRO map gives decimal address 19000 as a Float32 voltage in V.

Read PDU
03 4A 38 00 02: FC03, literal address 19000 (0x4A38), two registers.
Decode
Default bank is big-endian IEEE-754 Float32. Synthetic bytes 43 66 00 00 represent 230.0 V.
Alternate bank
Only if the client needs the documented little-endian representation, use address 19000 + 32768 = 51768.
Acceptance
Compare a fresh full-width reading with the simultaneous device/reference voltage after CT/VT settings are confirmed.

Acceptance: The payload is synthetic and proves only the stated decoder arithmetic. Real communication, firmware and transformer configuration remain site acceptance checks.

  1. Identify the instrument

    Record UMG 605-PRO model, firmware, supply and installed CT/VT ratios. The retained map applies from firmware 5.028.

  2. Match the serial settings

    Confirm the RS-485 operating role and actual unit address, speed and framing. Poll the server role only after checking site ownership of the port.

  3. Read L1-N voltage

    Read FC03 at literal decimal address 19000, quantity 2, in the default big-endian bank; do not subtract one.

  4. Check the decoder and scaling

    Decode a full IEEE-754 Float32 in V and compare with the instrument or a simultaneous reference. The float already includes configured transformer factors.

  5. Add current, power and frequency

    Add L1 current at 19012 (0x4A44) in A, total active power at 19026 (0x4A52) in W and frequency at 19050 (0x4A6A) in Hz. Read each complete value with FC04, quantity 2, big-endian IEEE-754 Float32, multiplier 1. For example, the current request PDU is 04 4A 44 00 02. These Float readings include the configured transformer factors; do not apply CT/VT ratios again. Compare current and signed power with the display under a known load. Keep the printed bank and decoder together; use the separate +32768 bank only with its little-endian decoder.

Common questions

Does the firmware matter for this address list?
Yes. The retained UMG 605-PRO list explicitly applies to firmware release 5.028 and higher. Check the installed release before using address 19000.1
Should Edge apply the CT ratio to the Float voltage or power again?
No. Janitza says Float and integer readings already include configured transformer factors. The short-format readings have a different scaling rule.1
Can ordinary polling retrieve recorded power-quality events?
This read covers live Modbus addresses. Recorded event and transient retrieval needs a separate documented path and should not be inferred from an instantaneous point.12

Sources

  1. UMG 605-PRO Modbus address list, document 1.038.009.7.h, firmware 5.028+ (opens in a new tab) (PDF) Janitza
  2. UMG 605-PRO user manual and technical data, document 1.038.027.1.u (opens in a new tab) (PDF) Janitza
  3. UMG 605-PRO product description (opens in a new tab) Janitza

Further reading

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