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Modbus Register Map

General Modbus Registers

In this chapter, we will cover the initial section of the modbus register map. We explore the different types of registers and their corresponding functions, as well as the various data types and their representations within the modbus protocol.

Glossary

  • u8: 8-bit unsigned integer.
  • u16: 16-bit unsigned integer.
  • u32: 32-bit unsigned integer.
  • f32: IEEE 754 single-precision floating-point value.
  • string: A null-terminated string of ASCII characters.
  • read: Modbus input register.
  • read/write: Modbus holding register.

Register List

Name
Address (Hexadecimal)
Address (Decimal)
Type
Unit
# Registers
Access
Modbus Address
0x0000
0
u8
1
read/write
Base Unit SKU
0x0001
1
u32
2
read
Supplier Name
0x0003
3
string
5
read
Modbus UART Baud Rate
0x0008
8
u32
2
read/write
Base Unit Hardware Version
0x000A
10
string
2
read
Base Unit Firmware Version
0x000C
12
string
6
read
Base Unit Serial Number
0x0012
18
u32
2
read
Polling Interval
0x0014
20
u32
secs
2
read/write
≥ 0 - Polling interval in seconds.
No. of Tags
0x0016
22
u8
1
read
Status
0x0017
23
u16
1
read
Device Name
0x0018
24
string
4
read/write
Reset Data
0x001C
28
1
write
Enable Licences
0x001D
29
write
≥ 2.0.0 ————————————————————————————————————————
Modbus Parity
0x0026
38
u8
1
read/write
Modbus Stop Bits
0x0027
39
u8
1
read/write

Modbus Address (Address = 0)

Address (16 bit)
Address (10 bit)
Type
# Registers
Access
Default Value
0x0000
0
u8
1
read/write
0x01
The Modbus Address register is used to set or get the slave address over the Modbus protocol.

Base Unit SKU (Address = 0x0001)

Address (Hexadecimal)
Address (Decimal)
Type
Unit
# Registers
Access
Default Value
0x0001
1
u32
2
read
The Base Unit SKU register holds the Stock Keeping Unit (SKU) of the base unit.

Supplier Name (Address = 0x0003)

Address (Hexadecimal)
Address (Decimal)
Type
Unit
# Registers
Access
Default Value
0x0003
3
ASCII String
5
read
Sensorbee
The Supplier Name register is used to store the name of the supplier of the base unit. It is a null terminated ASCII string.

Modbus UART Baud Rate (Address = 0x0008)

Address (Hexadecimal)
Address (Decimal)
Type
Unit
# Registers
Access
Default Value
0x0008
8
u32
2
read/write
9600
The Modbus UART Baud Rate register is used to set or get the baud rate of the Modbus UART communication.

Base Unit Hardware Version (Address = 0x000A)

Address (Hexadecimal)
Address (Decimal)
Type
Unit
# Registers
Access
Default Value
0x000A
10
Firmware Version
2
read
0
The Base Unit Hardware Version register holds the firmware version of the base unit.

Base Unit Hardware Version (Address = 0x000C)

Address (Hexadecimal)
Address (Decimal)
Type
Unit
# Registers
Access
Default Value
0x000C
12
string
6
read
The Base Unit Firmware Version register holds the hardware version of the base unit. It is a null terminated string.

Base Unit Serial Number (Address = 0x0012)

Address (Hexadecimal)
Address (Decimal)
Type
Unit
# Registers
Access
Default Value
0x0012
18
u32
2
read
0
The Base Unit Serial Number register holds the serial number of the base unit.

Polling Interval (Address = 0x0014)

Address (Hexadecimal)
Address (Decimal)
Type
Unit
# Registers
Access
Default Value
0x0014
20
u32
secs
2
read/write
5
The Polling Interval register is used to set or get the time interval between data collections. A value of 0 indicates manual mode and data can be collected whenever required.
⚠️
Manual mode is currently not supported yet.

No. of Tags (Address = 0x0016)

Address (Hexadecimal)
Address (Decimal)
Type
Unit
# Registers
Access
Default Value
0x0016
22
u8
1
read
0
The No. of Tags register holds the number of tags in the base unit.

Status (Address = 0x0017)

Address (Hexadecimal)
Address (Decimal)
Type
Unit
# Registers
Access
Default Value
0x0017
23
u16
1
read
0
The Status register holds the status of the base unit.

Device Name (Address = 0x0018)

Address (Hexadecimal)
Address (Decimal)
Type
Unit
# Registers
Access
Default Value
0x0018
24
string
4
read/write
The Device Name register holds the name of the device. The string is null-terminated unless all registers are used to store the string.

Reset Data (Address = 0x001C)

Address (Hexadecimal)
Address (Decimal)
Type
Unit
# Registers
Access
Default Value
0x001C
28
Any
1
write
The Reset Data register is used to reset the maximum and minimum statistics for data collected during polling.

Enable Licences (Address = 0x001D)

Address (Hexadecimal)
Address (Decimal)
Type
Unit
# Registers
Access
Default Value
0x001D
29
u8
1
read/write
0: None
This register is used to enable the license for the noise sensor.

Modbus Parity (Address = 0x0026) (≥ 2.0.0)

This register can be used to control the parity configuration of the Modbus serial interface. The register can be configured to the following values:
  • 0: None
  • 1: Odd
  • 2: Even
⚠️
After setting the value in this register, a reboot must take place for the change to take effect.

Modbus Stop Bits (Address = 0x0027) (≥ 2.0.0)

This register can be used to set or get the stop bit configuration of the Modbus serial interface. The register can be configured to the following values:
  • 1: 1 stop bit
  • 2: 2 stop bits
⚠️
After setting the value in this register, a reboot must take place for the change to take effect.

Additional Information

For detailed information about additional Modbus registers, please refer to:
Modbus Register Map 2Modbus Register Map 2Modbus Register Map 3Modbus Register Map 3Modbus Gas Register MapModbus Gas Register Map