HMS Networks (Intesis) · Protocol gateway
INMBSSAM001R100 – Samsung NASA units to Modbus RTU interface Modbus register map
Default configuration
- Protocol
- RS485
- Port
- 502
- Unit ID
- 1
- Addressing
- 0-based
- Byte order
- Big endian
- Word order
- High word first
- Baud rate
- 9600
- Parity
- None
- Data bits
- 8
- Stop bits
- 2
This device has an RS-485 interface. Reach it through a Modbus RTU-to-TCP gateway, configured with the factory serial settings above.
Register map
| Address | Count | Name | Type | Unit | Scale | Access |
|---|---|---|---|---|---|---|
| 0 | 1 | AC unit on/off 0 = off, 1 = on. | UInt16 | - | 1 | RW |
| 1 | 1 | AC unit mode 0 = Auto, 1 = Heat, 2 = Dry, 3 = Fan, 4 = Cool; the available values depend on the indoor unit. | UInt16 | - | 1 | RW |
| 2 | 1 | AC unit fan speed 0 = Auto, 1 = Low, 2 = Mid, 3 = High, 4 = Turbo. | UInt16 | - | 1 | RW |
| 3 | 1 | AC unit up/down vane position 0 = swing off (auto), 10 = swing on. | UInt16 | - | 1 | RW |
| 4 | 1 | AC unit temperature setpoint -32768 = initialization value; cooling 18..30 °C (raw 180..300 at the factory degC x10 setting), heating 16..30 °C, 65..86 °F. | Int16 | °C | 0.1 | RW |
| 5 | 1 | AC unit temperature reference -32768 = initialization value; -41..38 °C. | Int16 | °C | 0.1 | R |
| 6 | 1 | Window contact 0 = closed (default), 1 = open. | UInt16 | - | 1 | RW |
| 7 | 1 | Gateway disablement 0 = INMBSSAM001R100 enabled (default), 1 = disabled. Stored in non-volatile memory. | UInt16 | - | 1 | RW |
| 8 | 1 | AC remote control disablement 0 = remote controller enabled (default), 1 = disabled. Stored in non-volatile memory. | UInt16 | - | 1 | RW |
| 9 | 1 | AC unit operation time 0..65535 hours, counts the time the indoor unit is in the 'On' state. | UInt16 | h | 1 | RW |
| 10 | 1 | AC unit alarm status 0 = no alarm condition, 1 = alarm condition. | UInt16 | - | 1 | R |
| 11 | 1 | Error code 0 = no error; 65535 (= -1) = communication error between gateway and AC indoor unit; any other value is listed in the manual's error-code table. | UInt16 | - | 1 | R |
| 13 | 1 | 'Open Window' switch-off timeout 0..30 minutes; factory setting 30. | UInt16 | min | 1 | RW |
| 14 | 1 | Modbus RTU baud rate 2400 / 4800 / 9600 (default) / 19200 / 38400 / 57600 / 76800 / 115200 bps. | UInt16 | - | 1 | R |
| 15 | 1 | Modbus slave address 1..63. | UInt16 | - | 1 | R |
| 22 | 1 | Indoor unit ambient temperature from external sensor -32768 = no external sensor value; otherwise a temperature supplied from the Modbus side. | Int16 | °C | 0.1 | RW |
| 23 | 1 | AC real temperature setpoint Current setpoint in the indoor unit; equals register 4 when no external temperature is provided; 16..31 °C. | Int16 | °C | 0.1 | R |
| 26 | 1 | AC unit left/right vane position 0 = swing off (auto), 10 = swing on. | UInt16 | - | 1 | RW |
| 40 | 1 | Window contact on/off disablement 0 = the window contact is not disabling on/off (default), 1 = it is. | UInt16 | - | 1 | R |
| 43 | 1 | Filter reset Write 1 to reset the filter sign. | UInt16 | - | 1 | W |
| 44 | 1 | Filter status 0 = ok, 1 = filter cleaning required. | UInt16 | - | 1 | R |
| 49 | 1 | Device ID 0x2E00. | UInt16 | - | 1 | R |
| 50 | 1 | Software version Gateway firmware version. | UInt16 | - | 1 | R |
| 66 | 1 | Return path temperature -32768 = initialization value; the range is specific to the indoor unit. | Int16 | °C | 0.1 | R |
| 67 | 1 | Number of indoor units connected Indoor units on the same remote-control bus. | UInt16 | - | 1 | R |
| 68 | 1 | Internal indoor-unit array index reported Position in the gateway's internal array of the indoor unit whose status is currently reported. | UInt16 | - | 1 | RW |
| 69 | 1 | Indoor unit address reported Address of the indoor unit that reports its status on the remote-control bus. | UInt16 | - | 1 | R |
| 97 | 1 | Block periodic sendings 0 = non-blocked (default), 1 = blocked. | UInt16 | - | 1 | RW |
| 99 | 1 | Reset / reboot device Write 1 to reset the gateway. | UInt16 | - | 1 | W |
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Related guides
Notes
Source: HMS Networks / Intesis user manual 'INMBSSAM001R100 (Samsung NASA) Samsung NASA units to Modbus RTU interface', r1.4, section 4.2 'Modbus Registers' (4.2.1 control and status, 4.2.2 configuration). The gateway is Modbus RTU (RS-485) and exposes its own fixed holding-register map that mirrors the indoor unit; reach it through a Modbus RTU-to-TCP gateway using the factory serial settings above (9600 bps, 8-N-2, Modbus server address 1; the gateway auto-detects 8-N-1 and 8-N-2). All registers are 16-bit unsigned holding registers, big-endian. The addresses in this file are the manual's base-0 'protocol addresses' (the manual also prints a base-1 'PLC address', which is always this address + 1). Temperature registers are signed 16-bit and their magnitude follows the gateway's DIP switches (degC x1, degC x10 or degF), so the 0.1 scale factors below assume the factory default degC x10; with the x1 setting the readings are whole degrees. This file covers the NASA variant of the Samsung gateway; the older non-NASA order code INMBSSAM001R000 has its own manual and a different indoor-unit addressing block. Registers 68/69 report which indoor unit on the remote-control bus the gateway is currently reporting status for.