LSIS XBL-C41A

Chapter 9 Modbus Communication
9-13
(3) Frame example
Example writing 10 continuous bits starting 20
th
address of 1 server acting as Modbus RTU mode
Ex.) Data value to write continuously
Bit value 1 1 0 0 1 1 0 1 0 0 0 0 0 0 0 1
Hex C D 0 1
Address 27 26 25 24 23 22 21 20 - - - - - - 29 28
(a) Request frame
Classifica
tion
Station
no.
Function
code
Address No. of output
Data
size
Output
Error
check
Upper byte
Lower
byte
Upper
byte
Lower
byte
Upper
byte
Lower
byte
Frame 01 0F 00 13 00 0A 02 CD 01 CRC
(b) Response frame (In case receiving normal frame)
Classifica
tion
Station no. Function code
Address No. of output
Error
check
Upper byte Lower byte Upper byte Lower byte
Frame 01 04 00 13 00 0A CRC
(c) Response frame (In case of receiving abnormal frame)
Classifica
tion
Station no. Function code Exceptional code Error check
Frame 01 8F 01 CRC