User Manual

Chengdu Ebyte Electronic Technology Co., Ltd. E108-D01 User Manual
Copyright ©2012–2022, Chengdu Ebyte Electronic Technology Co., Ltd.
11
order: big endian, byte order: big endian;
Speed over ground
40213
00D5
Float
(4Byte)
The unit is Kn, read-only, word order: big endian,
byte order: big endian;
Course over
ground
40215
00D7
Float
(4Byte)
The unit is Kn, read-only, word order: big endian,
byte order: big endian;
Note Single-precision floating-point uses the standard IEEE754 format, with a total of 32 bits (4 bytes). The
default single-precision floating point endian mode is ABCD (high byte first, low byte last), for example: 0x3FF1EB85
represents 1.89 (reserved 2 decimal places).
5. Use of Modbus RTU
NoteIn the following demo, the device address is 1. If using a different device address, then the address bits and
checking code are different from below values.
5.1 Holding Registers
The register used by E108-D01 is holding register. The function code for writing the holding register is 0x06 (write
a single holding register), and reading the holding register uses 0x03 (reading the holding register)
0x03 code read instruction format (take the read version as an example):
Device address
Function code
First address
Read quantity
Check code CRC
01
03
00 01
00 01
D5 CA
Return format (take the read version as an example):
Device address
Function code
Data length
Read quantity
Check code CRC
01
03
02
00 10
B9 88
0x06 code configuration command format (configure device address as an example):
Device address
Function code
Data length
Value
Check code CRC
01
03
00 02
00 01
25 CA
Return format (configured device address as an example): the same as the command format;
5.2 Read Holding Register Instruction
5.2.1 Read version number
Command frame: 01 03 00 01 00 01 D5 CA
Address
Function code
Register start address
Number of
registers
CRC check
0x01
0x03
0x00 0x01
0x00 0x01
0xD5 0xCA
Response frame: 01 03 02 00 10 B9 88