Wilo Stratos IF-Module pump

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
set_value_holding	1	U16	0.5	%
pump_command_holding	40	U16	1
operation_mode_holding	42	U16	1
bus_command_timer	300	U16	1
set_value_input	400	U16	0.5	%
pump_command_input	402	U16	1
operation_mode_input	10	U16	1
test_register_700	700	U16	1

link settings as documented (unverified): RTU; default 9600 8E1; unit ID 1; Frame formats configurable via Parameter C (Menu 5.2.5.0). Default is 8,E,1 (Code 6).

⚠ When bus command timer state is RESET, writes from Modbus to the Setvalue, Pump command and Operation mode (holding registers 1, 40, 42) have no effect. — Starkest reads only; we never write a control register.

bench facts as documented (unverified)

terminals	marked with a (-) and b (+)
A/B polarity	a (-) and b (+)
termination	activated by setting both switches (located close to connection terminals) in the position marked with a non crossed thru resistor symbol
shield/ground	Shield shall be connected to chassis ground on both ends of the cable as a standard.
wiring notes	Characteristic impedance of the pair shall be 120 Ohm. Wiring shall be done with real shielded twisted pairs.
protocol notes	If input register 700 read fails, try 701 (offset issue).
identification notes	Software version is on a sticker close to mains terminal at Stratos series and can be read out at 4.4.2.0 for all other pump types.
accuracy	The flow value refers to clean water. Any additives may result in inaccurate or useless values.
doc revision	2014-01-03
firmware applicability	WILO Stratos series >= 5.09, WILO Stratos GIGA (all), WILO BL-E (all), WILO IP-E/DP-E >= 3.00, WILO IL-E/DL-E >= 4.00, WILO Helix EXCEL (all), WILO MVIE/MHIE/HELIX VE (1,1..4 kW) >= 3.00, WILO MVIE/HELIX VE (5,5..7,5 kW) >= 4.00

⚠ disputed: baud_rates: [9600] — disputed by Wilo Modbus IF-Module Guide, which states that multiple baud rates from 300 to 115200 bps are supported and configurable via Parameter A (Menu 5.2.4.0)

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

Depending on the Modbus master/client system, a register offset of 1 may apply. If reading input register 700 (30701) fails, users should try reading 699 or 701 to detect the offset. [source]
Some manufacturers of automation equipment use the opposite marking of A and B compared to Wilo's A(-) and B(+) terminals, which can cause RS485 communication issues. [source]
confirmed: Default baud rate is 9600, default unit ID is 1, and default framing is 8,E,1 (Code 6) — confirmed by Wilo Modbus IF-Module Guide [1.1.6]
confirmed: When bus command timer state is RESET, writes from Modbus to the Setvalue, Pump command, and Operation mode (holding registers 1, 40, 42) have no effect — confirmed by Wilo Modbus IF-Module Guide
confirmed: The flow value refers to clean water and additives may result in inaccurate or useless values — confirmed by Wilo Modbus IF-Module Guide
confirmed: Wiring terminals are marked with a (-) and b (+) and termination is activated by setting both switches to the non-crossed-thru resistor symbol — confirmed by Wilo Modbus IF-Module Guide
confirmed: If input register 700 read fails, try 701 (or 699) to detect potential register offset — confirmed by Wilo Modbus IF-Module Guide

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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