Carlo Gavazzi EM24-DIN

Three-phase energy meter

EM24-DIN combines local energy readout with direct or transformer-operated inputs. The IS option adds RS-485 Modbus. Its measurements use scaled integers with the low word first, so a correct address alone is not enough: verify word order, sign and scale before enabling the rest of the map.

Carlo Gavazzi EM24-DIN
  • Modbus RTU

Three-phase energy meter

Download Edge template

Compatibility

Compatible through Modbus RTU

The manufacturer publishes the measurement register map and communication settings used by an Edge Modbus client.

EM24-DIN PFA, PFB and X models with the IS RS-485 option. M1 M-Bus, DP Dupline and EM24 Ethernet are separate interfaces; the Ethernet map is not interchangeable.

Connect it with

Route into Edge

When the meter is away from the Gateway

  • Modbus
  • Wireless
  • Edge
  • Platforms
Three-phase energy meter
Interface
Gateway
Edge
Output
EM24-DINEM24-DIN RS-485
ZMB-31Modbus RTU to the EpiSensor wireless network
ZGW-20 GatewayHosts Edge locally
EpiSensor EdgeModbus client + register map
Customer platformMQTT · API · files
Modbus RTU · RS-485
EpiSensor wireless
Runs locally
Optional onward data
Retain the installed unit address and serial settings. The ZMB-31 reads the meter over its local RS-485 bus and carries the measurements wirelessly to the Gateway. The customer-platform output is optional; Edge remains the local system of record.

When an isolated RS-485 interface is available at the Gateway

  • Modbus
  • Edge
  • Platforms
Three-phase energy meter
Interface
Gateway
Edge
Output
EM24-DINEM24-DIN RS-485
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
Use one active master on the serial segment. Record the serial settings from the meter and match them in Edge; adding a second poller to an occupied bus can cause collisions. The customer-platform output is optional; Edge remains the local system of record.

Specifications

The EM24-DIN is a three-phase energy analyser in a 4-module DIN-rail housing, with a joystick and LCD for local readout and set-up. Carlo Gavazzi builds it for active and reactive energy metering and for cost allocation. It measures phase and system voltage, current, active, apparent and reactive power, power factor and frequency, and keeps total and partial kWh and kvarh counters, with up to four tariffs.1

Active energy accuracy
Class 1 (EN 62053-21); Class B (EN 50470-3)1
Reactive energy accuracy
Class 2 (EN 62053-23)1
Direct connection (AV2, AV9)
10(65) A per phase1
CT connection (AV5, AV6)
1/5(10) A secondary1
Voltage (AV5)
160 to 480 V L-N, 277 to 830 V L-L1
Systems (standard versions)
3-phase 4-wire and 3-wire, 2-phase 3-wire, 1-phase 2-wire1
Legal metrology
MID certified with the PF option; only the total imported energy counter is certified1
Dimensions
71 × 90 × 64.5 mm, 4 DIN modules1
Protection
IP50 front, IP20 terminals1
Operating temperature
-25 to 55 °C, 0 to 90 % RH non-condensing1
RS-485 settings
Unit address 1–247; 4800 or 9600 bit/s; match installed parity and stop bits1
Auxiliary power
AV2/AV9: measured supply. AV5/AV6: ordering option L 18–60 V AC/DC or D 115/230 V AC1
Read request size
Up to 11 registers per request unless the protocol specifies otherwise; up to 500 ms response time2

Interface

This register map is for the EM24-DIN PFA/PFB/X RS-485. AV2 / AV9 with IS, AV5 / AV6 with IS and M1, DP or Ethernet variants have their own interfaces and are not covered here.

Communication settings

Protocol
Modbus RTU (JBUS) over RS-485
Unit address
1 to 247
Baud rate
4800 or 9600 bit/s, set on the meter
Parity and stop bits
Set on the meter; the instruction manual lists the options
Registers per request
Up to 11
Response time
40 ms typical, 500 ms maximum
Bus termination
120 Ω between A and B at both ends of the bus
Bus loading
1/5 unit load; a repeater is needed beyond 160 meters on one bus or 1,000 m of cable
Read with
FC04 (FC03 returns the same values)
Word order
Low word first on each 32-bit value
Addresses
Zero-based PDU addresses, as sent on the bus

From EM24-DIN PFA, PFB & X models - Communication Protocol2.

Register map

Download
PointAddressHexFormatScaleUnit
Voltage L1-N 0 0x0000 INT32 ×0.1 V
Voltage L2-N 2 0x0002 INT32 ×0.1 V
Voltage L3-N 4 0x0004 INT32 ×0.1 V
Voltage L1-L2 6 0x0006 INT32 ×0.1 V
Voltage L2-L3 8 0x0008 INT32 ×0.1 V
Voltage L3-L1 10 0x000A INT32 ×0.1 V
Current L1 12 0x000C INT32 ×0.001 A
Current L2 14 0x000E INT32 ×0.001 A
Current L3 16 0x0010 INT32 ×0.001 A
Active Power L1 18 0x0012 INT32 ×0.1 W
Active Power L2 20 0x0014 INT32 ×0.1 W
Active Power L3 22 0x0016 INT32 ×0.1 W
Apparent Power L1 24 0x0018 INT32 ×0.1 VA
Apparent Power L2 26 0x001A INT32 ×0.1 VA
Apparent Power L3 28 0x001C INT32 ×0.1 VA
Reactive Power L1 30 0x001E INT32 ×0.1 VAr
Reactive Power L2 32 0x0020 INT32 ×0.1 VAr
Reactive Power L3 34 0x0022 INT32 ×0.1 VAr
Average Voltage L-N 36 0x0024 INT32 ×0.1 V
Average Voltage L-L 38 0x0026 INT32 ×0.1 V
Total Active Power 40 0x0028 INT32 ×0.1 W
Total Apparent Power 42 0x002A INT32 ×0.1 VA
Total Reactive Power 44 0x002C INT32 ×0.1 VAr
Power Factor L1 50 0x0032 INT16 ×0.001 -
Power Factor L2 51 0x0033 INT16 ×0.001 -
Power Factor L3 52 0x0034 INT16 ×0.001 -
Total Power Factor 53 0x0035 INT16 ×0.001 -
Frequency 55 0x0037 INT16 ×0.1 Hz
Import Active Energy 62 0x003E INT32 ×0.1 kWh
Import Reactive Energy 64 0x0040 INT32 ×0.1 kVArh
Export Active Energy 92 0x005C INT32 ×0.1 kWh
Export Reactive Energy 94 0x005E INT32 ×0.1 kVArh

Download the EM24-DIN PFA/PFB/X RS-485 register map as CSV

Assessment

EM24-DIN PFA, PFB and X models with the IS RS-485 option. M1 M-Bus, DP Dupline and EM24 Ethernet are separate interfaces; the Ethernet map is not interchangeable.

InteroperabilityWell supported
A published serial map specifies both read functions, physical addresses, signed formats, word order and scaling.2
AccuracySupported with conditions
The datasheet defines direct and CT inputs plus Class 1 active and Class 2 reactive energy. Certified imported energy is limited to the PF option.1
SecurityNot yet assessed
The reviewed documents do not establish authenticated or encrypted register access. Network security requires a separate installation review.2
ReliabilitySupported with conditions
Maximum response time, request limits and explicit overflow behaviour are documented and can be handled by the reader.2
RuggednessSupported with conditions
IP50 front, IP20 terminals and -25 to +55 °C define an enclosed DIN-rail installation.1
ScalabilitySupported with conditions
Addressed RS-485 supports multiple meters, with finite bus loading, length and response time. Those limits must be budgeted together.12
LifecycleSupported with conditions
The manufacturer retains an identifiable datasheet and versioned protocol for the PFA/PFB/X scope. Keep both with the installed order code.12

Edge template

This JSON file supplies the register map. Applying it to an existing meter replaces its sensor list while retaining the site connection, unit ID and enable state.

ModelConnectionPointsVersionUpdatedDownload
EM24-DIN PFA/PFB/X RS-485 Modbus RTU (JBUS) over RS-485 32 1.0.0 Download

Downloads need a signed-in account with Edge download access.

Use the template in Edge

  1. Import the JSON file

    In Edge, open Settings, then Devices and Templates. Choose Import JSON and select the downloaded file. Confirm that the model and template name match your device.

  2. Load the map for your meter

    For a new Modbus device, use Load Template before entering the manufacturer or model; it fills those fields and the register list. Set the name, site connection and unit ID, check the polling enable state, then test before saving. For an existing device, apply only to the matching model; this replaces its sensor list but retains its connection, unit ID and enable state.

  3. Test a reading

    Use Test in the wizard and compare a known reading with the meter display. Check its unit, sign and scale, then confirm that timestamps keep advancing. These starter maps are read-only and leave exports off until you configure them.

Setup

Read L1-N voltage as a scaled integer

Use the physical address column in the EM24-DIN PFA/PFB/X communication protocol, version 4 revision 0.

Function
FC04 Read Input Registers; FC03 returns the same measurement values
PDU start
0 (0x0000), two registers
Format
Signed INT32; least significant word first, high byte first inside each word
Scale
0.1 V per count; no additional CT multiplier on voltage
Independent vector
A simulated 230.0 V value is raw 2300 = 0x000008FC. Returned words 0x08FC, 0x0000 become bytes 08 FC 00 00.
Request PDU
04 00 00 00 02; the Modbus client adds the actual unit address and CRC
Invalid value
A high word of 0x7FFF indicates overflow and must not be treated as measured voltage

Acceptance: The vector tests decoding only. Compare several fresh readings with the meter display, then repeat with current and signed power. A swapped-word integer can still look plausible at one operating point.

  1. Read the complete order code

    Confirm IS RS-485 and the input range: AV2/AV9 direct connection or AV5/AV6 CT secondary. Record the installed CT ratio and auxiliary supply where applicable. Do not treat an Ethernet EM24 as the same register map.

  2. Connect one serial master

    Use a two-wire RS-485 bus with the documented reference and end termination. Match the unit address, 4800 or 9600 bit/s and the installed parity/stop settings. Resolve ownership of an existing bus before adding a reader.

  3. Verify one scaled integer

    Read voltage L1-N at PDU address 0 with FC04 and two registers. Decode signed INT32, low word first, high byte first within each word, then multiply by 0.1 V. Compare fresh values with the display on a wiring mode that provides L1-N.

  4. Import the existing Edge template

    Download and import the 32-point EM24-DIN RS-485 core template. Keep requests within the documented 11-register limit. Check current and signed total power against the local display before enabling every point.

  5. Handle invalid readings and counters

    The protocol flags overflow with 0x7FFF in the high word. Do not export that as a numeric reading. Preserve communications failure and stale states separately from zero. This read-only setup does not reset energy or change CT ratios.

Common questions

Which EM24-DIN models have Modbus?
Models with the IS option in the order code have an RS-485 port that speaks Modbus RTU, plus three digital inputs. The M1 option is M-Bus and the DP option is Dupline, and neither speaks Modbus.1
Are the EM24 register addresses zero-based?
Yes. The addresses on this page are the protocol document’s hexadecimal addresses used as zero-based PDU addresses, so Voltage L1-N is input register 0. A master that uses 30001-style numbering shows it as 30001.2
How are 32-bit values ordered?
Carlo Gavazzi sends the least significant word first, with the most significant byte first inside each word. In Edge that is big-endian bytes with word swap on every INT32 register.2
Can the EM24-DIN be used for billing?
The datasheet identifies the PF option as MID certified and limits the certified quantity to total imported active energy. Exported energy and the other measurements are outside that stated certification; verify the installed order code and meter markings.1

Sources

  1. EM24 DIN three-phase energy analyzer datasheet (DS 260315) (opens in a new tab) (PDF) Carlo Gavazzi
  2. EM24-DIN PFA, PFB & X models - Communication Protocol (opens in a new tab) (PDF) Carlo Gavazzi

Further reading

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