Modbus

The following is a complete overview of the Modbus registers and functions for your STATOTEST-LASER device:

📋 MODBUS REGISTERS AND FUNCTIONS

📖 READ HOLDING REGISTERS (0x03)

Address	Type	Description	Unit	Range	Example
0	uint16	Device status	-	0-1	1 (active)
1	uint16	Firmware version	-	0-65535	1
2	uint16	Hardware version	-	0-65535	2
3	uint16	Measurement state	-	0-4	0=idle, 2=measuring, 3=done, 4=continuous
4	uint16	Distance (low part)	0.1mm	0-65535	12345 (=1.2345m)
5	uint16	Distance (high part)	0.1mm	0-65535	0
6	uint16	Laser state	-	0-1	0=OFF, 1=ON
7	uint16	Temperature	0.1°C	-400-800	235 (=23.5°C)
8	uint16	Voltage	0.1V	0-100	33 (=3.3V)
9	uint16	Signal quality	%	0-100	85
10	uint16	Device address	-	1-254	1
11	uint16	Baudrate code	-	1-7	4 (=19200)
12	uint16	Error code	-	0-17	0=OK
13	uint16	Bluetooth state	-	0-1	1=enabled
14	uint16	WiFi state	-	0-1	0=disabled

Special distance reading:

• Address 4, 2 words: Returns the complete 32-bit distance (low + high part)
• Address 4, 1 word: Returns only the low part of the distance
• Address 5, 1 word: Returns only the high part of the distance

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🔧 WRITE SINGLE REGISTER (0x06)

Address	Function	Values	Description	Example
3	Measurement control	0=stop, 1=single, 4=continuous	Starts/stops a measurement	1
5	Laser control	0=OFF, 1=ON	Turns the laser on/off	1
10	Address setting	1-254	Changes the Modbus address	5
11	Baudrate setting	1-7	Changes the RS485 speed	4
13	Bluetooth control	0=disable, 1=enable	Turns BT on/off	1
14	WiFi control	0=disable, 1=enable	Turns WiFi on/off	1

Baudrate codes (address 11):

Code	Baudrate
1	2400
2	4800
3	9600
4	19200
5	38400
6	57600
7	115200

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🔀 WRITE SINGLE COIL (0x05)

Address	Function	Values	Description
13 (0x0D)	Start measurement	0x0000=stop, 0xFF00=start	Alternative way to start a measurement

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⚙️ COMMUNICATION CONFIGURATION

Parameter	Value
Default address	1
Default baudrate	19200
Data bits	8
Parity	None
Stop bits	1
Broadcast address	255 (supported)

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📏 MEASUREMENT DATA FORMAT

Distance (32-bit):

• Unit: 0.1 mm (0.0001 m)
• Range: 0 - 4294967295 (0-429496.7295 m)
• Example: 12345 = 1.2345 m

Temperature:

• Unit: 0.1°C
• Range: -40.0°C to +80.0°C
• Example: 235 = 23.5°C

Voltage:

• Unit: 0.1V
• Range: 0.0V to 10.0V
• Example: 33 = 3.3V

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🚨 ERROR CODES (Address 12)

Code	Description
0	No error
1	Low voltage
2	Internal error
3	Low temperature
4	High temperature
5	Target out of range
6	Invalid result
7	Background too strong
8	Weak reflected signal
9	Strong reflected signal
10-14	Hardware errors
15	Vibration too high
16-17	Hardware errors

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📋 COMMAND EXAMPLES

Reading the distance (32-bit):

Command: 01 03 00 04 00 02 CRC
Response: 01 03 04 30 39 00 00 CRC
Result: 12345 = 1.2345 m

Starting a measurement:

Command: 01 06 00 03 00 01 CRC
Response: 01 06 00 03 00 01 CRC

Turning the laser on:

Command: 01 06 00 05 00 01 CRC  
Response: 01 06 00 05 00 01 CRC

Setting the address to 5:

Command: 01 06 00 0A 00 05 CRC
Response: 01 06 00 0A 00 05 CRC

Starting a measurement via Write Coil:

Command: 01 05 00 0D FF 00 CRC
Response: 01 05 00 0D FF 00 CRC

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🔄 MEASUREMENT STATES (Address 3)

State	Description
0	Idle
2	Measurement in progress
3	Measurement completed
4	Continuous measurement

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⚠️ NOTES

• Broadcast address 255 is supported for all functions
• Configuration changes are saved to the flash memory
• A measurement automatically resets the state to 0 after it is read
• Continuous measurement runs until it is stopped
• All registers are read-only except addresses 3, 5, 10, 11, 13, 14