Danfoss VLT AutomationDrive FC 302 Modbus register map

Also searched as: FC 302 · FC302 · FC 301 · VLT AutomationDrive FC 301/302

19 Modbus registers of the Danfoss VLT AutomationDrive FC 302, with the address on the wire, the 30001-style reference, data type, byte order, unit and scale. Transcribed from Programming Guide VLT AutomationDrive FC 301/302 (software versions 9.12, 48.9X) (2022.12).

VLT AutomationDrive FC 301/302 built-in Modbus RTU; drive parameters are holding registers at parameter number x 10 minus 1.

Registers Read it by name

AI assistant · MCP Product UI · sample data

Map: danfoss/vlt-automationdrive-fc-302Read-only

MCP · read_named reading… ✓ 4 values · 38 ms

read_named(device: "vlt-1", keys: ["motor_voltage", "motor_current", "output_frequency", "reference_pct"])

motor_voltage 230.4 V

motor_current 12.6 A

output_frequency 42.50 Hz

reference_pct 72.5 %

Device type: Variable speed drive
Registers: 19
Interfaces: Modbus RTU
Byte order (multi-register values): ABCD

Hardware verification

Not yet verified on hardware. The map is transcribed from the vendor document and checked against it by script; check the first readings against the device display.

Verify it on your device What the levels mean

Connection notes

Set 8-30 Protocol to Modbus RTU [2], 8-31 Address, 8-32 FC Port Baud Rate and 8-33 Parity / Stop Bits (default even parity, 1 stop bit) before connecting.
Every parameter is a holding register at parameter number x 10; the address sent on the wire is that register minus 1 (1-00 is register 1000, address 999 = 0x03E7 in the guide's example frame).
32-bit parameters span two registers, high word first; read them with a count of 2.
Array parameters need the index written to holding register 9 first; none are listed here.
Writing parameters changes drive behaviour and can move the motor. Read-only access is the safe default.

Registers

Grouped as in the vendor document.

Status 4 registers

Name and key	Reference	Address	Type	Byte order	Unit	Scale
Control word (16-00)`control_word`	416000	0x3E7F	bitfield16
Reference [unit] (16-01)`reference_unit`	416010	0x3E89	int32	ABCD		× 0.001
Reference % (16-02)`reference_pct`	416020	0x3E93	int16		%	× 0.1
Status word (16-03)`status_word`	416030	0x3E9D	bitfield16

Motor 5 registers

Name and key	Reference	Address	Type	Byte order	Unit	Scale
Motor voltage (16-12)`motor_voltage`	416120	0x3EF7	uint16		V	× 0.1
Frequency (16-13)`output_frequency`	416130	0x3F01	uint16		Hz	× 0.1
Motor current (16-14)`motor_current`	416140	0x3F0B	int32	ABCD	A	× 0.01
Torque [Nm] (16-16)`torque_nm`	416160	0x3F1F	int16		Nm	× 0.1
Motor thermal (16-18)`motor_thermal`	416180	0x3F33	uint16		%

Drive 4 registers

Name and key	Reference	Address	Type	Byte order	Unit	Scale
DC link voltage (16-30)`dc_link_voltage`	416300	0x3FAB	uint16		V
Inverter thermal (16-35)`inverter_thermal`	416350	0x3FDD	uint16		%
Inverter nominal current (16-36)`inverter_nominal_current`	416360	0x3FE7	uint32	ABCD	A	× 0.01
Inverter maximum current (16-37)`inverter_max_current`	416370	0x3FF1	uint32	ABCD	A	× 0.01

I/O 1 registers

Name and key	Reference	Address	Type	Byte order	Unit	Scale
Digital input (16-60)`digital_inputs`	416600	0x40D7	uint16

Diagnostics 5 registers

Name and key	Reference	Address	Type	Byte order
Alarm word (16-90)`alarm_word`	416900	0x4203	uint32	ABCD
Alarm word 2 (16-91)`alarm_word_2`	416910	0x420D	uint32	ABCD
Warning word (16-92)`warning_word`	416920	0x4217	uint32	ABCD
Warning word 2 (16-93)`warning_word_2`	416930	0x4221	uint32	ABCD
Extended status word (16-94)`ext_status_word`	416940	0x422B	uint32	ABCD

Source documents

Programming Guide VLT AutomationDrive FC 301/302 (software versions 9.12, 48.9X) , Danfoss A/S, AU275636650261en-000101 / 130R0334, 2022.12 (accessed 2026-11-09) Data type and conversion index of each parameter (group 16-** Data Readouts).
Modbus RTU Operating Instructions , Danfoss A/S, MG92B102 (accessed 2026-11-09) Sections 4.1.12-4.1.18 and 6.1: parameter number x 10 rule, 32-bit byte mapping and example frames (1-00 at address 999, 3-03 at 3029, 1-24 at 1239). Written for the FC series with built-in Modbus RTU.

View this map on GitHub (YAML)

Read it by name

Read the VLT AutomationDrive FC 302 with an AI assistant

The Proxus Industrial MCP Server includes this map. Set it on the device, and Claude, Cursor or VS Code reads registers by key with the right type, byte order, scale and unit. It only reads.

This device speaks Modbus RTU: reach it through a Modbus TCP gateway and use the gateway’s address with the device’s unit ID.

Get the MCP server

proxus-mcp.json

{
  "devices": {
    "vlt-1": {
      "protocol": "modbus-tcp",
      "host": "192.168.10.40",
      "unit_id": 1,
      "map": "danfoss/vlt-automationdrive-fc-302"
    }
  }
}

Ask your assistant

Read reference_pct from vlt-1.

The tool call it makes

read_named(device: "vlt-1", keys: ["reference_pct"])

Have this device? Verify the map.

Ask your assistant to run verify_device_map. It reads every register once, read-only, checks that the values are plausible and asks you to compare two values with the display. You get a report and a prefilled GitHub issue to submit; your name goes on this map’s verified list.

How verification works

Collecting from many devices?

Proxus reads Modbus TCP and RTU devices next to the machines, keeps the history and delivers the values to dashboards, databases and AI.

Modbus in Proxus Industrial connectivity