Honeywell UDC2500/3200/3300 controller (Modbus comms option)

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 only confirmed at the hardware-verified rung.

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
pv_integer	0	I16	0.1	Prescale * 10
remote_set_point_integer	1	I16	0.1
working_set_point_integer	2	I16	0.1	Prescale * 10
output_integer	3	I16	0.1	Prescale * 10
input_1_integer	4	I16	0.1
input_2_integer	5	I16	0.1
pv_float	64	F32BE	1	EU
remote_set_point_float	66	F32BE	1	EU
working_set_point_float	68	F32BE	1	EU
output_float	70	F32BE	1	EU
input_1_float	72	F32BE	1	EU
input_2_float	74	F32BE	1	EU
analog_input_1	6144	F32BE	1	EU
analog_input_2	6146	F32BE	1	EU
analog_input_3	6148	F32BE	1
analog_input_4	6150	F32BE	1
totalizer_1	6912	F32BE	1	EU
totalizer_2	6914	F32BE	1
alarm_status_1_16	7152	U16	1
alarm_set_point_1	7168	F32BE	1	EU
alarm_set_point_2	7170	F32BE	1

link settings as documented (unverified): RTU; baud 300/600/1200/2400/4800/9600/19200/38400; FC 01,02,03,04,05,06,08,16,17,20,21

bench facts as documented (unverified)

wiring notes	The Modbus RTU allows the instrument to be a citizen on a data link shared with other devices that subscribe to the Modbus RTU RS-485 specification.
max registers/read	22
broadcast	not supported
protocol notes	Request delay time is 20 ms (or 3.5 characters for newer versions).
identification notes	Uses Function Code 17 (11h) to report Device ID.
FC 43 device ID	not supported
doc revision	Revision T

generated by gemini:gemini-3.5-flash · harvested from https://www.lesman.com/amfile/file/download/file/28/product/2221/ (Honeywell); manual-faithful — the document's claims, panel risk: ELEVATED — panel is not confident; proved interop-verified on 2026-06-10 · recorded 2026-06-10

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.

Have a device that isn't here? Upload its register map — generation is free, and the connector earns its rung by being proven, not claimed.

Need it proven on your own device? Hardware verification — if it doesn't verify, you don't pay.

Building a platform? License the verified library — machine-readable maps, firmware matrix, API access.