Grundfos MAGNA3/MGE/MPC pumps (needs CIM 200 Modbus module)

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
head	300	U16	0.001	bar
volume_flow	301	U16	0.1	m³/h
relative_performance	302	U16	0.01	%
speed	303	U16	1	rpm
frequency	304	U16	0.1	Hz
actual_setpoint	307	U16	0.01	%
motor_current	308	U16	0.1	A
dc_link_voltage	309	U16	0.1	V
motor_voltage	310	U16	0.1	V
power	311	U32BE	1	W
remote_flow	313	U16	0.1	m³/h
inlet_pressure	314	I16	0.001	bar
remote_pressure_1	315	I16	0.001	bar
feed_tank_level	316	I16	0.01	m
power_electronic_temp	317	U16	0.01	K
motor_temp	318	U16	0.01	K
remote_temp_1	319	U16	0.01	K
electronic_temp	320	U16	0.01	K
pump_liquid_temp	321	U16	0.01	K
bearing_temp_de	322	U16	0.01	K
bearing_temp_nde	323	U16	0.01	K
aux_sensor_input	324	U16	0.01	%
specific_energy_consumption	325	U16	1	Wh/m³
operation_time	326	U32BE	1	h
total_powered_time	328	U32BE	1	h
torque	330	U16	0.1	Nm
energy	331	U32BE	1	kWh
number_of_starts	333	U32BE	1
remote_temp_2	336	U16	0.01	K
user_setpoint	337	U16	0.01	%
diffpressure	338	U16	0.001	bar
outlet_pressure	339	U16	0.001	bar
remote_pressure_2	340	U16	0.001	bar
load_percent	341	U16	0.01	%
max_flow_limit	344	U16	0.1	m³/h
remote_diff_temp	345	U16	0.01	K
inlet_diff_pressure	346	U16	0.001	bar
outlet_diff_pressure	347	U16	0.001	bar
remote_diff_pressure	348	U16	0.001	bar
storage_tank_level	349	I16	0.01	m
ambient_temp	350	U16	0.01	K
heat_energy_counter_1	351	U32BE	1	kWh
heat_power	353	U32BE	1	W
heat_diff_temp	355	U16	0.01	K
volume_1	356	U32BE	0.01	m³
heat_energy_counter_2	358	U32BE	1
volume_2	360	U32BE	0.01	m³
conductivity	362	U16	0.1	NTU
ph_measure	363	U16	0.01	pH
turbidity	364	U16	1	uS/cm

link settings as documented (unverified): RTU/TCP; default 19200 8E1; unit ID 231; FC 03,04,06,08,16; Default transmission speed is 19200 bits per second. Default parity is Even parity (1 stop bit). Default Modbus address is 231 (0xE7).

bench facts as documented (unverified)

terminals	Conductors: D0, D1 and Common for CIM 200; A, Y, B for SoftCIM
A/B polarity	D1 is positive, D0 is negative
termination	DIP switches SW1 and SW2 on CIM 200
connector	Screw-type terminal
shield/ground	Connect the cable screen to protective earth at both ends
max registers/read	125
broadcast	supported
protocol notes	Telegrams must be separated by a silent interval of at least 3.5 times the character time.
model register	29
firmware register	33
power	24-240 V
environment	Operating temperature -20 to +45 °C, Ambient humidity 30 % to 95 % Relative, non-condensing
doc revision	05.2025

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

Siemens S7-1200 MB_CLIENT write operations fail to update pump parameters if the zero-based address offset is not correctly configured (e.g., register 40100 must be addressed as 99 in MB_CLIENT). [source]
Users report that writing to holding registers requires using 'write multiple holding registers' (Function Code 16) rather than 'write single register' (Function Code 06) to avoid values not updating or getting strange results. [source]
confirmed: Baud rates [1200, 2400, 4800, 9600, 19200, 38400] with default 19200 — confirmed by Grundfos Modbus manual
confirmed: Default unit ID 231 — confirmed by Grundfos Modbus manual
confirmed: Framing RTU and TCP — confirmed by Grundfos Modbus manual covering both CIM 200 (RTU) and CIM 500 (TCP)
confirmed: Function codes 3, 4, 6, 8, 16 — confirmed by Grundfos Modbus manual
confirmed: Parity Even, 1 stop bit — confirmed by Grundfos Modbus manual
confirmed: Identification registers (firmware at 33, model at 29, 0-based) — confirmed by Grundfos Modbus manual (1-based 34 and 30)
confirmed: Physical connector (Screw-type terminal), polarity (D1 positive, D0 negative), shield ground, terminals, and termination — confirmed by Grundfos Modbus manual
confirmed: Power 24-240 V — confirmed by Grundfos Modbus manual for CIU unit

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.