LSIS XBL-C41A

Chapter 9 Modbus Communication
9-15
(3) Frame example
Example writing continuous 2 words starting 20
th
address of server 1acting as Modbus RTU mode
Ex.) value to write continuously
Hex C D 0 1 0 0 0 A
Address 20 21
(a) Request frame
Classific
ation
Station
no.
Functio
n code
Address
No. of output
Data
size
Output
Error
check
Upper
byte
Lower
byte
Upper
byte
Lower
byte
Frame 01 10 00 13 00 02 04 CD 01 00 0A CRC
(b) Response frame (In case receiving normal frame)
Classific
ation
Station no.
Function
code
Address No. of output
Error
check
Upper byte Lower byte Upper byte Lower byte
Frame 01 10 00 13 00 02 CRC
(c) Response frame (In case of receiving abnormal frame)
Classifica
tion
Station no. Function code Exceptional code Error check
Frame 01 90 01 CRC