Michell Easidew EA2 dew-point transmitter (M12 Modbus variant)

Register map(s) for this device, each at the trust rung it earned. Addresses are 0-based as on the wire. Word order and scaling are confirmed at the hardware-verified rung and at no rung below it.

interop-verified

Read + decoded cleanly over a real network vs an independent third-party Modbus test server (transport and framing; reads are remapped into the server's register window, so the map's own addresses are NOT exercised). Does NOT prove word order/scaling against the actual device.

point	address (0-based)	type	scale	unit
humidity_parameter	1	I16	0.1	°C
ambient_temperature	2	I16	0.1	°C
status_fault_indication	3	U16	1
pressure_value_for_ppmv	54	I16	0.1	barg

link settings as documented (unverified): RTU; default 9600 8N1; FC 03,06,16; The RS485 interface on the DIN version is intended for configuration and diagnostics and should only be used with a Michell Instruments communications kit. The M12 version of the transmitter should be used if continuous monitoring or measurement via the RS485 / Modbus interface is required.

⚠ Incorrect wiring of the transmitter may result in permanent damage. — Starkest reads only; we never write a control register.

bench facts as documented (unverified)

terminals	M12 5-way A coded connector or MiniDIN 43650 form C
A/B polarity	Modbus A, Modbus B
connector	M12 5-pin (A coded) or MiniDIN 43650 form C
shield/ground	Pin 5 (Grey) / GND (Blue) directly connects to the metal casing of the transmitter, but not to the transmitter electronics, and is intended for cable screening only.
wiring notes	Recommended to use 3-core screened cable.
serial register	16
firmware register	8
identification notes	Sensor Batch Number is at register 15.
power	12...28 V DC, 23 mA max
environment	Operating temperature: -40...+60 °C, Compensated temperature range: -20...+50 °C, Storage temperature: -40...+60 °C, Operating pressure: 45 MPa (450 barg) maximum
accuracy	±2°C dew point
certifications	CE, UKCA, UL approved (UL61010-1 & CAN/CSA C22.2 No. 61010-1), ATEX/UKCA: II 1 G Ex ia IIC T4 Ga (-20...+70 °C), IECEx: EX ia IIC T4 Ga (-20...+70 °C), TR CU@ 0Ex ia IICT4 Ga (-20...+70 °C), cQPSus: Class I, Division 1, Groups A B C D, T4
doc revision	97504 Issue 3.3, March 2022

field reports — community-sourced, unverified (checked 2026-06-11)

confirmed: comms defaults (9600 baud, RTU, 8N1, FC 3/6/16) — confirmed by the Easidew Dew-Point Transmitter User Manual (97504 Issue 3.3, March 2022, Appendix B)
confirmed: DIN vs M12 RS485 usage note — confirmed by the Easidew Dew-Point Transmitter User Manual (Section 2.2.4)
confirmed: accuracy (±2°C dew point) — confirmed by the Easidew Dew-Point Transmitter User Manual (Appendix A)
confirmed: certifications (CE, UKCA, UL, ATEX, IECEx, TR CU, cQPSus) — confirmed by the Easidew Dew-Point Transmitter User Manual (Appendix A)
confirmed: environmental limits (-40...+60 °C operating, -20...+50 °C compensated, 45 MPa max pressure) — confirmed by the Easidew Dew-Point Transmitter User Manual (Appendix A)
confirmed: power requirements (12...28 V DC, 23 mA max) — confirmed by the Easidew Dew-Point Transmitter User Manual (Appendix A)
confirmed: connector pinout and shield ground behavior (Pin 5 Grey / GND Blue directly connects to metal casing for screening only) — confirmed by the Easidew Dew-Point Transmitter User Manual (Section 2.2.2.1)
confirmed: identification registers (firmware @ 8, batch @ 15, serial @ 16) — confirmed by the Easidew Dew-Point Transmitter User Manual (Appendix B)

The trust ladder

Each rung states what it proved and what it did not. Gray until proven; green is earned by hardware only.

generated — A prompt produced it. Unproven — anyone can regenerate this.
structure-verified — Decode path is structurally sound (addresses, widths, finite values). Does NOT prove word order or scaling.
interop-verified — Read + decoded cleanly over a real network vs an independent third-party Modbus test server (transport and framing; reads are remapped into the server's register window, so the map's own addresses are NOT exercised). Does NOT prove word order/scaling against the actual device.
simulator-verified — Decoded correctly against a protocol emulator seeded with known-true values — catches word-order/scaling errors vs the emulator, not the physical device.
hardware-verified x1 — Matched a real device with operator-attested readings as ground truth — the only rung that confirms word order + scaling on the wire.

If your device isn't here, upload its register map. Generation is free, and the connector keeps the rung it earns under testing.

To prove a connector against your own device, order hardware verification. If it doesn't verify, you don't pay.

Platform builders can license the verified library: machine-readable maps, the firmware matrix, API access.