LG GLOFA-GM Series User Manual page 202

Chapter 7 Communication function
1 Program download start command(PDN, PDD)
This downloads the program data after receiving ACK response as a result of execution of program download
start command. This service must be performed within 1 sec. after response of program download start command.
Also, the delay time of each program download sequence service must be within 1 sec.
1) Request Format(PC -> PLC)
Format
Header
Name
Frame (Ex.) ENQ
ASCII value H05
Frame No. indicates the current frame number (4 Bytes) to be downloaded in the entire download sequence.
This number must be incremental in sequence until the download finishes completely. Frame No. increases
in sequence from 0001.
This indicates the number of data included in this frame. It can include up to 120 Bytes.
Data shall be set as agreed with the max. size(120 Bytes) if possible.
For the last frame, surely set frame No. to HFFFF(46,46,46,46).
If the last frame No. isn't set to HFFFF, download execution is regarded as finished abnormally without
download completed.
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( When PLC response ACK)
Format
Header
Name
Frame (Ex.) ACK
ASCII value H06
Station number, commands, type of command, frame No., and number of data 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.
If frame No. is not HFFFF after receiving the frame, the next frame shall be sent within 1 sec.
Station Command
Command
No. type
H01 P(p) DX
H3031 H50(70) H4458
Station Command
Command
No. type
H01 P DX
H3031 H50 H4458
7-83
frame NO Number of data
(HEX 4 Bytes) (HEX 1Bytes)
H0001 H10
H30303031 H3130
Frame NO Number of data
(HEX 4 Bytes) (HEX 1 Byte)
H0001
H30303031 H3130
Frame
data Tail
check
EOT BCC
H04
Frame
Tail
check
H10 ETX BCC
H03