Modbus – KWh meter – Eastron SDM120


Info (ENG)

SDM120-Modbus, Single-Phase Multifunction DIN rail Meter

  • Measures kWh, Kvarh, KW, Kvar, KVA, PF, Hz, dmd, V, A, etc.
  • Bi-directional measurement IMP & EXP
  • Two pulse outputs
  • RS485 Modbus
  • Din rail mounting 17.5mm
  • 45A direct connection
  • Better than Class 1 accuracy

The energy-meters “with a blue back-lighted LCD screen for prefect reading” are used to measure single-phase like residential, utility and Industrial application. The unit measures and displays various important electrical parameters, and provide a RS485 communication port for remote reading and monitoring. Bi-directional energy measurement makes the unit a good choice for solar PV energy metering. The compact design and din rail installation provides a easy and economical solution for your metering demand

Performance criteria:
Operating humidity ≤ 85%
Storage humidity ≤ 95%
Operating temperature -20°C – +50°C
Storage temperature -30°C – +70°C
International standard IEC 62053-21
Accuracy class 1
Protection against penetration
of dust and water IP51
Insulating encased meter of
Protective class Ⅱ

Meter type SDM120A (Mechanical register display)
SDM120D (LCD display)
SDM120DB (LCD with backlit)
Nominal voltage (Un) 230V AC
Operational voltage 161 – 300V AC
Insulation capabilities:
– AC voltage withstand 2KV for 1 minute
– Impulse voltage withstand 6KV – 1.2µS waveform
Basic current (Ib) 5A
Maximum rated current (Imax) 45A
Operational current range 0.4% Ib- Imax
Over current withstand 30Imax for 0.01s
Operational frequency range 50Hz ±10%
Internal power consumption ≤2W / 10VA
Test output flash rate (RED LED) 1000imp/kWh (2000imp/kWh optional)
Pulse output rate (pins 6 & 7) 1000imp/kWh (2000imp/kWh optional)
Consumption indicator (RED LED) Flashing at load running

Ps. De vraag of deze meters hun meterstanden onthouden na stroomuitval: Ja, getest bij de modbus RS485 versie.



Mobus registers

Function code 04 to read input parameters:

Input Register Parameter Modbus Protocol Start
Address Hex
Parameter Units Format Hi byte Lo byte
30001 Voltage Volts Float 00 00
30007 Current Amps Float 00 06
30013 Active power Watts Float 00 0C
30019 Apparent power VA Float 00 12
30025 Reactive power VAr Float 00 18
30031 Power factor None Float 00 1E
30071 Frequency Hz Float 00 46
30073 Import active energy kWh Float 00 48
30075 Export active energy kWh Float 00 4A
30077 Import reactive energy kvarh Float 00 4C
30079 Export reactive energy kvarh Float 00 4E
30343 Total active energy kWh Float 01 56
30345 Total reactive energy Kvarh Float 01 58

Function code 10 to set holding parameter function code 03 to read holding parameter

Holding Register Parameter Modbus Protocol
Address Hex
Parameters Format Hi byte Lo byte
40013 Relay Pulse
Float 00 0C Write relay on period in
milliseconds: 60, 100 or 200,
default 100ms.
40019 Network Parity
Float 00 12 Write the network port parity/stop
bits for MODBUS Protocol, where:
0 = One stop bit and no parity,
default. 1 = One stop bit and even
parity. 2 = One stop bit and odd
parity.3 = Two stop bits and no
parity.Requires a restart to
become effective.
40021 Meter ID Float 00 14 Ranges from 1 to 247,
.Default ID is 1.
40029 Baud rate Float 00 1C 0:2400bps(default)
40087 Pulse 1 output
Hex 00 56 0001: Import active energy,
0002: Import + export active
0004: Export active energy,
0005: Import reactive energy,
0006: Import + export reactive
0008: Export reactive energy,
463745 Time of scroll
BCD F9 00 0-30s
Default 0:does not display in turns
463761 Pulse 1 output Hex F9 10 0000:0.001kWh/imp(default)
463777 Measurement
Hex F9 20 Data FormatHex
0001:mode 1(total = import)
0002:mode 2
(total = import + export
0003:mode 3
(total = import – export)


Voorbeeld uitlezen

Fabriek gegevens
Standaard adres: 1
Baud rate: 2400

Voorbeeld uitlezen met pymodbus 2.4.0+ versie:

Voorbeeld baudrate instellen pymodbus v2.4.0+ versie: