Eastron · Three-phase energy meterSDM630-Modbus
The SDM630-Modbus V2 is a direct-connected three-phase meter with RS-485 Modbus RTU and two pulse outputs. Edge can acquire its documented electrical measurements through ZMB-31 or an approved serial interface.
Choose the connection that matches the model
This guide covers the direct-connected SDM630-Modbus V2 over RS-485. SDM630-TCP, SDM630-Mbus, pulse-only, dual-tariff and SDM630MCT variants are separate products; do not assume their interfaces, wiring or register maps are interchangeable.
System architecture
RS-485 through ZMB-31
For a remote meter where a wireless bridge avoids a new long data-cable route
System architecture
Direct serial Modbus client
When an approved isolated serial interface is available at the Gateway
Match the exact model to its interface
Use the complete catalogue number, not the family name, when selecting an Edge connection.
| Models | Documented interface | EpiSensor route |
|---|---|---|
| SDM630-Modbus V2 | RS-485 Modbus RTU · two pulse outputs · direct connection up to 100 A | ZMB-31 wireless bridge or an approved direct serial interface |
| SDM630-TCP | Ethernet Modbus TCP · separate product | Engineer and document as a separate Ethernet integration |
| SDM630-Mbus / Mbus-2T | Wired M-Bus · separate product | Use a qualified M-Bus master path; this Modbus map does not apply |
| SDM630MCT family | 1 A / 5 A CT-operated variants with their own wiring and documents | Select and qualify the exact MCT model independently |
What Edge can exchange
The exact list depends on the model and its published data map. Start with the monitoring and control points the project will actually use.
- Phase-to-neutral voltage for 1P2W and 3P4W systems; the protocol marks these values unavailable for 3P3W where applicable
- Phase current and neutral current where the wiring mode supports the measurement
- Active, reactive and apparent power, power factor, phase angle and frequency
- Import, export and total energy values from the register set matched to the installed model
- Demand values and total harmonic distortion where the exact protocol revision exposes them
- Freshness and communications state so a stale value or failed poll is never presented as a measured zero
Commission the interface, then preserve the map
A successful network connection is the start of the check, not the end.
Read phase 1 line-to-neutral voltage
Use this check on an already installed 1P2W or 3P4W meter whose exact register map matches Eastron's V1.8 protocol document. It makes the 30001 display reference and the wire address explicit.
- Function
- FC04 Read Input Registers
- Document reference
- 30001
- PDU start
- 0 / 0x0000
- Length
- 2 registers
- Decode
- IEEE-754 float32 · confirm normal or reversed register order
- Engineering unit
- V · multiplier 1 · offset 0
Acceptance: Compare the decoded value with the same phase shown on the front panel at the same time. Retain the raw response and confirmed byte/word settings, then observe several fresh timestamps before adding more points.
- Confirm the front label says SDM630-Modbus V2 and record the firmware/build display. The reviewed user-manual file is labelled 2023 V1.5 on its cover while its running header says V1.4, so preserve the actual document used.
- Have a qualified person confirm the electrical connection mode and installation. The phase-1 line-to-neutral worked check is not valid as a general 3P3W voltage check.
- Record the installed slave address, baud rate, parity and stop bits rather than applying defaults. Coordinate with the existing bus master before attaching another interface.
- Check RS-485 polarity, common reference, topology, bias and termination across the complete bus. Do not use a communications check as authority to alter live panel wiring.
- Configure the read-only voltage point above first. The current user manual says word order is set automatically to normal or reverse and cannot be changed from the front-panel menu. Test Edge's normal and word-swapped decode against a stable non-zero display value, then retain the verified setting without writing the meter.
- Do not write holding registers, reset energy counters, alter the meter's word order or deliberately switch electrical loads as part of this check.
- Keep one poll within the meter's documented request size and schedule the whole bus using observed response times, not only theoretical serial timing.
- Treat missing or stale telemetry as invalid. Do not gap-fill a failed poll with zero, especially in demand, energy and alarm workflows.
Assessment
This assessment applies to Read-only three-phase monitoring from SDM630-Modbus V2 through Edge. It separates protocol compatibility from the quality of public evidence and keeps unsupported criteria visibly unknown.
The assessment covers the direct-connected RS-485 product and the manufacturer's V1.8 Modbus map. It excludes SDM630-TCP, M-Bus, pulse-only, dual-tariff and CT-operated variants.
Open interoperability
Well supportedThe product uses Modbus RTU over RS-485 and Eastron publishes function codes, zero-based start addresses, types and units for the meter.
Evidence: eastron-sdm630-product, eastron-sdm630-protocol, modbus-specification
Measurement fitness
Supported with conditionsThe meter publishes a broad three-phase measurement set, but availability changes with wiring mode and the direct-connected product must not be confused with CT-operated or differently certified variants.
Evidence: eastron-sdm630-product, eastron-sdm630-protocol, eastron-sdm630-manual
Security
LimitedThe front-panel configuration is password protected, but Modbus RTU provides no peer authentication or encryption. Physical access, bus ownership and protected upstream networking carry the security boundary.
Evidence: eastron-sdm630-product, eastron-sdm630-manual, modbus-specification
Reliability and recovery
Not yet assessedThe reviewed public documents do not establish comparable field-failure, bus-recovery or long-duration availability evidence for an Edge deployment.
No criterion-specific public evidence recorded.
Ruggedness
Supported with conditionsThe manufacturer publishes DIN-rail dimensions and operating limits; final suitability depends on the panel enclosure, conductor protection, temperature and installation category.
Evidence: eastron-sdm630-product, eastron-sdm630-manual
Scalability
Supported with conditionsAddressable RS-485 supports multi-drop deployment, while bus length, topology, termination, polling schedule, response time and a single-master operating model constrain scale.
Evidence: eastron-sdm630-product, eastron-sdm630-protocol
Lifecycle and maintainability
Supported with conditionsCurrent product, download and protocol pages are available, but the reviewed user-manual file carries inconsistent visible revision labels. Preserve the exact files and installed identity with the Edge template.
Evidence: eastron-sdm630-product, eastron-sdm630-manual, eastron-sdm630-protocol
Evidence quality
Supported with conditionsThe worked check comes from the manufacturer's protocol document and agrees with pinned implementation references, but the manual revision ambiguity and broad SDM630 naming require explicit scoping.
Evidence: eastron-sdm630-product, eastron-sdm630-manual, eastron-sdm630-protocol
Rubric device-integration-v1 · 7 of 8 criteria currently evidenced · no overall score is calculated.
Sources
- SDM630-Modbus V2 product page (opens in a new tab)
- SDM630-Modbus V2 User Manual, cover 2023 V1.5 (opens in a new tab) (PDF)
- SDM630Modbus Smart Meter Modbus Protocol Implementation V1.8 (opens in a new tab) (PDF)
- Modbus specifications and implementation guides (opens in a new tab)
Reviewed by EpiSensor technical review on . Revision 1. Product names and trademarks belong to their respective owners; this guide does not imply endorsement or a commercial relationship.