Diehl Sharky 775 heat meter

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
energy	0	U32BE	1
energy_float	8	F32BE	1
volume	10	U32BE	1
volume_float	18	F32BE	1
power	20	U32BE	1
power_float	28	F32BE	1
flow	30	U32BE	1
flow_float	38	F32BE	1
start_temperature	40	I16	1	°C
flow_temperature_float	46	F32BE	1	°C
return_temperature	48	I16	1	°C
return_temperature_float	54	F32BE	1	°C
temperature_difference	56	I16	1	°C
temperature_difference_float	62	F32BE	1	°C
tariff_1_energy	64	U32BE	1
tariff_1_energy_float	72	F32BE	1
tariff_1_volume	74	U32BE	1
tariff_1_volume_float	82	F32BE	1
tariff_2_energy	84	U32BE	1
tariff_2_energy_float	92	F32BE	1
tariff_2_volume	94	U32BE	1
tariff_2_volume_float	102	F32BE	1
pulse_input_1_volume	144	U32BE	1
pulse_input_1_volume_float	152	F32BE	1
pulse_input_2_volume	154	U32BE	1
pulse_input_2_volume_float	162	F32BE	1
error_code	164	U16	1
meter_id_no	165	U32BE	1

link settings as documented (unverified): RTU; default 9600 8N1; unit ID 1; FC 03,04,06,16; Automatic slave ID addressing option is enabled by default.

bench facts as documented (unverified)

terminals	Screw terminal 60 and 61 (power supply), Screw terminal 90 (+) and 91 (-) (EIA-485)
A/B polarity	Power supply: polarity-independent. EIA-485: polarity dependent (90 is +, 91 is -)
termination	Standard termination (120 Ohm) or termination with safety polarization (fail-safe biasing: RT = 138 Ohm, R1, R2 = 470 Ohm)
connector	Screw terminals
isolation	galvanically isolated
shield/ground	If shielded cable is used, shield shall not be connected or grounded.
wiring notes	Maximum EIA-485 channel length is 1,200 m. Recommended cable is BELDEN 9841 1x2x24AWG shielded twisted-pair or similar.
broadcast	supported
protocol notes	The Communication Module sends data with the most significant register first and the most significant byte first (no byte/word swap).
model register	32003
serial register	32001
firmware register	32005
identification notes	Meter ID no. is at 30166 (address 165).
power	12 - 24 V AC/DC ± 10%, Maximum input power 500 mW
environment	Operating temperature: 0 ... +55°C, Storage temperature: +5 ... +35°C
certifications	WEEE, CE (EN 50581:2012, EN 55032:2015, EN 55032:2015/A11:2020, EN 55035:2017, EN 55035:2017/A11:2020, EN 61000-3-2:2014, EN 61000-3-3:2013)
doc revision	12/2023

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

When the meter is battery-powered, setting the Modbus update interval to less than 3 minutes can cause the meter display to show error code 5. [source]
confirmed: Baud rates [1200, 2400, 4800, 9600, 14400, 19200, 38400, 56000, 57600, 115200] and default baud 9600 — confirmed by Diehl Metering Modbus RTU Communication Module User Guide
confirmed: Default unit ID 1 and RTU framing — confirmed by Diehl Metering Modbus RTU Communication Module User Guide
confirmed: Automatic slave ID addressing option is enabled by default — confirmed by Diehl Metering Modbus RTU Communication Module User Guide
confirmed: Modbus registers 32001 (serial), 32003 (model), and 32005 (firmware) — confirmed by Diehl Metering Modbus RTU Communication Module User Guide
confirmed: EIA-485 polarity dependent terminals 90 (+) and 91 (-) — confirmed by Diehl Metering Modbus RTU Communication Module User Guide
confirmed: Fail-safe biasing termination values RT = 138 Ohm, R1, R2 = 470 Ohm — confirmed by Diehl Metering Modbus RTU Communication Module User Guide
confirmed: Register map addresses (e.g., energy @ 0, volume @ 10, power @ 20, flow @ 30, error_code @ 164, meter_id_no @ 165) — confirmed by Diehl Metering Modbus RTU Communication Module User 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.
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.