Chapter 13. Dedicated Cnet communication for GM6
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In case that the register format of register No. is the reading of named variable
Format
name
Header
Station
No.
Command
Register
No.
Number of
blocks
Number of
data
Data
Tail
Frame
check
Frame
(Ex.)
ACK
H10
Y(y)
H1F
H01
H04
H9183AABB
ETX
BCC
ASCII
value
H06
H3130
H59(79)
H313F
H3031
H3034
H3931383341
414242
H03
•
Data format such as number of blocks and number of data is the same as the contents of variable writing.
•
Station number, commands, and register No. are the same as computer request format.
•
BCC : When main command is one of lower case(y), only one lower byte of the value resulted by adding 1 Byte
each to ASCII values from ACK to ETX is converted into ASCII, added to BCC, and sent.
(4) Response format(for PLC NAK response)
Format
name
Header
Station No.
Command
Register No.
Error code (Hex 2 Bytes)
Tail
Frame
check
Frame
(Ex.)
NAK
H10
Y(y)
H1F
H1132
ETX
BCC
ASCII
value
H15
H3130
H59(79)
H3146
H31313332
H03
•
Station number, commands, and register No. are the same as computer request format.
•
BCC : When command is one of lower case(y), only one lower byte of the value resulted by adding 1 Byte each
to ASCII values from NAK to ETX is converted into ASCII, added to BCC, and sent.
•
Error code is hex and 2 Bytes(ASCII code, 4 Bytes), which indicates type of error. For the details, see Appendix
‘A2. Error Code Table’.
