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Chapter 7 Communication function
7-81
9
BCC : When command is one of lower case(p), 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.
2)
Response format(for PLC of ACK response)
Format
Name
Header
Station No.
Command
Command type
Tail
Frame check
Frame (Ex.)
ACK
H10
P(p)
DN
ETX
BCC
ASCII value
H06
H3130
H50(70)
H444E
H03
9
Station number, commands, and type of command are the same as in computer request format.
9
BCC : When command is one of lower case(p), 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.
9
Surely perform download command within 1 sec. after PLC ACK response, or start command will be invalid.
Consequently, start command shall be executed again to download again.
3)
Response format(for PLC of NAK response)
Format
Name
Header
Station No.
Command
Command type
Error CODE
(HEX 2 Bytes)
Tail
Frame check
Frame Ex.)
NAK
H10
P(p) DN(D) H1132 ETX BCC
ASCII value
H15
H3130
H50(70) H444E(44) H31313332 H03
9
Station number, commands, and type of command are the same as in computer request format.
9
BCC : When command is one of lower case(p), 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.
9
Error code is HEX and 2 bytes(ASCII code, 4 bytes), which indicates type of error.