Chapter 13 RS-232C function of K200S MASTER-K
13-9
3) Response format ( PLC à External device : ACK response )
Format
name
Header
Station
number
Main
instruction
Instruction
type
blocks
Length of
data
Data Tail
Frame
check
Frame
example
ACK h20 R (r) SS h01 h02 hA9F3 ETX BCC
ASCII
value
h06 h3230 h52 (h72) h5353 h3031 h3032 h41394633
…
h03
⑤ Station number, main instruction, instruction type, and number of blocks are same as
the request format.
⑥ When the main instruction is small character (r), the lower byte of summation from
ACK to ETX is converted into ASCII format and added to frame as BCC check.
⑦ The length of data indicates that the following data occupies how many bytes before
converted to ASCII code. It is determined on basis of the data type included in
request format.
Data type Length of data
Bit ( X ) 1
Word ( W ) 2
⑧ In data area, the contents of assigned device are stored after converted to ASCII
code.
Example : When the contents is h48B0, the ASCII code will be h34384230
(Max. 16 blocks available)
Although the data type is bit, the data should be a byte because the minimum data unit is a
byte. If the content of bit is 0, the data is h00 (ASCII code : h3030) and if the content is 1, the
data is h01(ASCII code : h3031).
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