Xinje XD5 User Manual

236
Modbus-ASCII data structure
ASCII mode:
For Modbus ASCII（American Standard Code for Information Interchange）mode in serial
links, every 8-bit byte is sent as two ASCII characters. When communication links and
devices do not fit RTU mode timing monitor, we usually use the ASCII mode.
Note：One byte needs two characters, so ASCII mode has lower inefficiency than RTU
mode.
E.g.: Byte 0X5B will be encoded as two characters: 0x35 and 0x42（ASCII code 0x35
="5"， 0x42 ="B" ）.
ASCII mode frame check domain：Longitudinal Redundancy Checking (LRC)
ASCII mode frame description:
Start mark
Modbus no.
Function code
data
LRC
End mark
1 character
2 characters
2 characters
0~252*2
characters
2 characters
2 characters
0x3A
0x0D
0x0A
Format：
STX (3AH)
Start mark=3AH
Address code high bit
Communication position（no）：
Consist of 2 ASCII codes
Address code low bit
Function code high bit
Function code（command）：
Consist of 2 ASCII codes
Function code low bit
Instruction start ID
Command start bit：
Consist of 4 ASCII codes
Instruction start ID
Instruction start ID
Instruction start ID
Data length
Length from start to end：
Consist of 4 ASCII codes
Data length
Data length
Data length
LRC check high bit
LRC check code：
Consist of 2 ASCII codes
LRC check low bit
END high bit
End mark：
END Hi=CR（0DH），END Lo=CR
（0AH）
END low bit
2. Communication address：
00H：All Xinje XC series PLC broadcast—— slave stations do not response.
01H：Communicate with address 01H PLC.
0FH：Communicate with address 15H PLC.
10H：Communicate with address 16H PLC.
And so on, up to 254（FEH）.
3. Function and DATA：
Function
code
Function
Corresponding modbus
01H
Read coil
COLR
02H
Read input coil
INRR

Xinje XD5 Specifications

General

Brand	Xinje
Model	XD5
Category	Controller
Language	English