LG GLOFA-GM Series User Manual page 206

Chapter 7 Communication function
2) Response format(for PLC of ACK response)
Format
Header
Name
Frame(value) ENQ
ASCII value H05
DOMAIN_SIZE means the size of the domain saved in PLC. This size is of ASCII code converted from
decimal. Station number, commands, and type of command are the same as in computer request format.
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. Surely send
upload command within I sec. after receiving this frame.
3) Response format(for PLC of NAK response)
Format
Header
Name
Frame (Ex.) NAK
ASCII value H15
Station number, commands, and type of command are the same as in computer request format.
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.
Error code is HEX and 2 bytes(ASCII code, 4 bytes), which indicates type of error.
4) Example of use
In case Domain name is set to PLC_pgm.
(Computer request format)
Format
Header
Name
Frame (Ex.) ENQ
ASCII value H05
Station
Command Command type
No.
H01 P(p)
H3031 H50(70)
Station
Command Command type
No.
H10 P(p)
H3130 H50(70)
Station Command
Command
No. type
H01 P(p) UN
H3031 H50(70) H554E
7-87
DOMAIN_SIZE
(Dec 4 Bytes)
UN(D) 00001298
H554E(44) H3030303031323938
Error code
(HEX 2 Bytes)
UN H1132
H554E H31313332
DM_LEN DM_NAME
H07 PLC_pgm
H3037 H504C435F52570676D
Tail Frame check
ETX BCC
H03
Tail Frame check
ETX BCC
H03
Tail Frame check
EOT BCC
H04