Socomec DIRIS A40/A41 power meter

Register map(s) for this device, with a note of how far each has been checked. Addresses are 0-based, as on the wire. Scale and byte order are confirmed only at the hardware-verified rung.

coherence-checked

Round-trips through a real Modbus stack with no overlapping addresses and a word-order-sensitive codec — the map is internally coherent and wire-decodable. Does NOT prove byte-order or scaling match a real device: the emulator is seeded from the map's own types, so a uniformly wrong byte-order still round-trips. Only hardware-verified confirms byte-order/scale on the wire.

point	address (0-based)	type	scale	unit
hour_meter	50512	U32BE	0.01	1/100 h
phase_to_phase_voltage_u12	50514	U32BE	0.01	V/100
phase_to_phase_voltage_u23	50516	U32BE	0.01	V/100
phase_to_phase_voltage_u31	50518	U32BE	0.01	V/100
simple_voltage_v1	50520	U32BE	0.01	V/100
simple_voltage_v2	50522	U32BE	0.01	V/100
simple_voltage_v3	50524	U32BE	0.01	V/100
frequency	50526	U32BE	0.01	Hz/100
current_i1	50528	U32BE	0.001	mA
current_i2	50530	U32BE	0.001	mA
current_i3	50532	U32BE	0.001	mA
neutral_current	50534	U32BE	0.001	mA
active_power	50536	U32BE	0.01	kW/100 (Signed)
reactive_power	50538	U32BE	0.01	kvar/100 (Signed)
apparent_power	50540	U32BE	0.01	kVA/100
power_factor	50542	U32BE	0.001	0.001 (Signed)
active_power_phase_1	50544	U32BE	0.01	kW/100 (Signed)
active_power_phase_2	50546	U32BE	0.01	kW/100 (Signed)
active_power_phase_3	50548	U32BE	0.01	kW/100 (Signed)
reactive_power_phase_1	50550	U32BE	0.01	kvar/100 (Signed)
reactive_power_phase_2	50552	U32BE	0.01	kvar/100 (Signed)
reactive_power_phase_3	50554	U32BE	0.01	kvar/100 (Signed)
apparent_power_phase_1	50556	U32BE	0.01	kVA/100
apparent_power_phase_2	50558	U32BE	0.01	kVA/100
apparent_power_phase_3	50560	U32BE	0.01	kVA/100
power_factor_phase_1	50562	U32BE	0.001	0.001 (Signed)
power_factor_phase_2	50564	U32BE	0.001	0.001 (Signed)
power_factor_phase_3	50566	U32BE	0.001	0.001 (Signed)
partial_positive_active_energy	50780	U32BE	1	kWh
partial_positive_reactive_energy	50782	U32BE	1	kvarh
module_temperature	51457	U16	1
thd_u12	51536	U16	0.1
thd_u23	51537	U16	0.1
thd_u31	51538	U16	0.1
thd_v1	51539	U16	0.1
thd_v2	51540	U16	0.1
thd_v3	51541	U16	0.1
thd_i1	51542	U16	0.1
thd_i2	51543	U16	0.1
thd_i3	51544	U16	0.1
thd_in	51545	U16	0.1

link settings as documented (unverified): RTU; default 38400 8O1; unit ID 1; FC 03; PLC programming examples suggest default/matching port settings of 38.4/8/Odd/1 and Slave ID 1.

bench facts as documented (unverified)

terminals	Diris A10 RS-485 Port: NC, +, - (terminals 13, 15, 17). Diris A20 RS-485 Optional Module: +, -, 0.
termination	Diris A10: 120 ohm resistor supplied as loose component to connect between + and - terminals at last slave. Diris A20: Set the 2 DIP switches on the last module on the bus to ON.
shield/ground	Only link the shield to the end on one end to guarantee the same potential of the shield. There is no other required earthing.
power	Diris A20: 110 / 240 VAC, 120 / 250 VDC. Diris A10: 110-277 VAC.
environment	50 or 60 Hz distribution system. Max voltage across voltage-input terminals (V1, V2, V3, VN) 520VAC phase-to-phase or 300VAC phase-to-neutral. Max current of 6A on current-input terminals (I1, I2, I3).

⚠ field check could not confirm this document matches this device — treat with caution.

⚠ disputed: default_baud: 38400 — disputed by LabVIEW Modbus RTU RS-485 Communication Setup guide which states the default baud rate is 9600 bps [3.2.4]

⚠ disputed: default_unit_id: 1 — disputed by Polar Monitoring guide which states the default communication address is 5

⚠ disputed: physical terminals, termination, and power specifications — disputed by official manuals because the stated specifications are explicitly for DIRIS A10 and DIRIS A20 models, whereas the DIRIS A40/A41 has different specifications (e.g., auxiliary power supply of 110 to 400 VAC / 120 to 350 VDC)

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

Many Modbus masters and PLCs (such as Siemens S7-1200/1500 using MB_CLIENT) restrict holding register addresses to the 40001-49999 range, making it impossible to query the DIRIS A40's 5xxxx range directly. Users must map these to 4xxxxx (e.g., 450515 for register 50514) or use raw 0-based offsets. [source]
For DIRIS A40/A41 devices manufactured before January 2009 (using the old communication table), registers 50780 and 50782 correspond to 'Number of pulse meters' and 'pulse meter 1' respectively, whereas for devices manufactured from January 2009 onwards (using the new communication table), they correspond to 'Partial Positive Active Energy (Ea+)' and 'Partial Positive Reactive Energy (Er+)'. [source]
confirmed: Modbus RTU framing and Function Code 3 (Read Holding Registers) — confirmed by official Socomec DIRIS A40/A41 manual [2.3.3]
confirmed: Register addresses (e.g., hour_meter @ 50512, phase_to_phase_voltage_u12 @ 50514, simple_voltage_v1 @ 50520, frequency @ 50526, current_i1 @ 50528, active_power @ 50536, power_factor @ 50542, thd_u12 @ 51536, thd_v1 @ 51539, thd_i1 @ 51542) — confirmed by official Socomec DIRIS A40/A41 Modbus communication tables

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.
coherence-checked — Round-trips through a real Modbus stack with no overlapping addresses and a word-order-sensitive codec — the map is internally coherent and wire-decodable. Does NOT prove byte-order or scaling match a real device: the emulator is seeded from the map's own types, so a uniformly wrong byte-order still round-trips. Only hardware-verified confirms byte-order/scale on the wire.
hardware-verified (software-key) x1 — Matched a real device with operator-attested readings as ground truth — the only rung that confirms word order + scaling on the wire.

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