LSIS Master-K K1000S - Frame Structure; General Structures

Chapter 13 RS-232C function of K200S MASTER-K
13-4
13.4 Frame structure
13.4.1 General structures
1) Request frame ( External devices à CPU )
2) ACK response frame (CPU à External devices, when normal data is received)
3) NAK response frame (CPU à External devices, when abnormal data is received)
Header
(ENQ)
Station No Instruction
Instruction
type
Data
Tail
(EOT)
Frame
check
(BCC)
(Max. 256byte)
Header
(ACK)
Station No Instruction
Instruction
type
Data or NULL
Tail
(ETX)
Frame
check
(BCC)
(Max. 256byte)
Header
(NAK)
Station No Instruction
Instruction
type
Error code
( ASCII 4 byte)
Tail
(ETX)
Frame
check
(BCC)
(Max. 256byte)
Remark
The following table describes several control codes. They are importantly used in serial
communication, so they should be well acquainted.
Code Hex value Original word Description
ENQ (header) h05 Enquire Start of request frame
ACK (header) h06 Acknowledge Start of ACK response frame
NAK (header) h15 Not acknowledge Start of NAK response frame
EOT (tail) h04 End of text End of request frame
ETX (tail) h03 End text End of response frame