User Manual

MR24HPB1

8. Communication commands and parameter definitions

8.1 Definition and description of the frame structure

A. Frame structure definition

Starting

Code

Length of data

Function

codes

Address

code 1

Address

code 2

Data

Check Code

0X55

Lenth_L

Lenth_H

Command

Address_1

Address_2

Data

Crc16_L

Crc16_H

1 Byte

n Byte

1 Byte

B. Description of the frame structure

a. Start code: 1 Byte, fixed to 0X55.

b. Data length: 2 Byte, low byte before, high byte after.

Length = Data Length + Function Code + Address Code 1 + Address Code 2

+ Data + Checksum.

c. Function code: 1 Byte

Read command: 0X01

Write command: 0X02

Passive report command: 0X03

Active report command: 0X04

d. Address code: Address code 1

indicates the function classification, address code 2 indicates the specific

function.

See the description of address assignment and data information.

e. Data: n Byte