LG GLOFA-GM Series User Manual page 156

Chapter 7 Communication function
2) Sequence of command frame
A) Sequence of command request frame
Station
ENQ
No.
B) Sequence of download/upload frame
Station
ENQ
No.
Station
ENQ
No.
Station
ENQ
No.
Formatted
Command EOT
data
Start
data EOT
command
Formatted
Command EOT
data
Formatted
Command EOT
data
BCC
(PLC ACK response)
Station
ACK
No.
(PLC NAK response)
Station
NAK
No.
BCC
(Down/upload start command)
Station
ACK
No.
BCC
(Down/upload command frame number H0001)
Station
ACK
No.
(Down/upload end command
BCC
Frame number H'FFFF)
Station
ACK
No.
7-37
Data
Command ETX
or null
Error
Command ETX
code
Data
Command ETX
or null
Data
Command ETX
or null
Data
Command ETX
or null
BCC
BCC
BCC
BCC
BCC