GF Signet 9900 transmitter

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
status	0	U32BE	1
primary_reading	2	F32BE	1
secondary_reading	4	F32BE	1
measurement_type	6	U16	1
primary_units_of_measure_code	7	U16	1
secondary_units_of_measure_code	8	U16	1
modbus_address	9000	U16	1
network_termination	9001	U16	1
modbus_mode	9002	U16	1
baud_rate	9003	U16	1
parity	9004	U16	1
floating_point_endian	9005	U16	1
save_reboot	9006	U16	1
hsb_transactions	9103	U16	1
second_counter	9104	U16	1
bus_message_counter	9105	U16	1
bus_message_error_counter	9106	U16	1
slave_exception_counter	9107	U16	1
slave_message_counter	9108	U16	1
slave_no_response_counter	9109	U16	1
slave_nak_counter	9110	U16	1
slave_busy_counter	9111	U16	1
bus_character_overrun_counter	9112	U16	1

link settings as documented (unverified): RTU/ASCII; default 19200 8E1; unit ID 34; RTU is Default Mode. Data Bits and Stop Bits are automatically selected based on Mode (RTU: 8 data, 1 stop; ASCII: 7 data, 2 stop).

bench facts as documented (unverified)

terminals	Terminal board (M2 version), M12 Connector (M3 version), Wire Cable pig tail (M4 version)
A/B polarity	D0 is RS485 -, D1 is RS485 +
termination	Internal programmable network termination enabled by Modbus command
connector	M12 or Terminal board or pig tail
shield/ground	Com/Reset GND
protocol notes	Write 0 to register 49007 to save user device identification registers. Write Modbus Address to 49007 to save communication settings and reboot.
model register	49561
serial register	49591
firmware register	49602
identification notes	Vendor Name at 49501, Product Code at 49516, Major/Minor Revision at 49526, Modbus Module Serial Number at 49596
power	12 to 24 VDC Nominal, 10.6 to 32 VDC max regulated. Do not exceed 32 VDC.
doc revision	3-9900.270.090 Rev 3 02/19

generated by gemini:gemini-3.5-flash · harvested from https://www.instrumart.com/assets/9900-Modbus-manual.pdf (Georg Fischer); manual-faithful — the document's claims, panel risk: LOW — panel concurs, no field disagreements; 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.