LSIS Master-K K1000S - Page 156

Chapter 13 RS-232C function of K200S MASTER-K
13-10
4) Response format ( PLC à External device : NAK response )
Format
name
Header
Station
number
Main
instruction
Instruction
type
Error code
(Hex 2 byte)
Tail Frame check
Frame
example
NAK h20 R (r) SS h2232 ETX BCC
ASCII value h15 h3230 h52 (h72) h5353 h32323332 h03
⑨ Station number, main instruction, and instruction type are same as the request format.
⑩ When the main instruction is small character (r), the lower byte of summation from
NAK to ETX is converted into ASCII format and added to frame as BCC check.
⑪ The error code is expressed as 2 byte of hexadecimal format ( 4bytes of ASCII
codes) and indicates the type of error. Please refer the error code table for details.
5) Example
Read the contents of first word of P area ( P000 ) and 21
th
word of M area ( M020 ) from
the PLC of that station number is h01. Assume the contents of P000 is h1234, and M020
is h3456. ( No BCC check )
⑫ Request format (External device à PLC)
Format
name
Header
Station
number
Main
instruction
Instruction
type
Number
of blocks
Length of
device
definition
Device
definition
Length of
device
definition
Device
definition
Tail
Frame
example
ENQ h01 R SS h02 h06 %PW000 h06 %MW020 EOT
ASCII
value
h05 h3031 h52 h5353 h3032 h3036
h255057
303030
h3036
h254D57
303230
h04
⑬ Response format (PLC à External device : ACK response)
Format
name
Header
Station
number
Main
instruction
Instruction
type
Number
of blocks
Length of
data
Data
Length of
data
Data Tail
Frame
example
ACK h01 R SS h02 h02 h1234 h02 h3456 EXT
ASCII
value
h06 h3031 h52 h5353 h3032 h3032 h31323334 h3032
h3334
3536
h03
⑭ Response format (PLC à External device : NAK response)
Format
name
Header
Station
number
Main
instruction
Instruction
type
Error code Tail
Frame
example
NAK h01 R SS
error code
(2 byte)
ETX
ASCII value h15 h3031 h52 h5353
ASCII value
(4 byte)
h03