LS Industrial Systems GLOFA G7M-DR20U/DC - Page 246

Chapter 8. Communication Functions
8-20
(4) GM7U main unit response format (NAK response)
Format name Header
Station
No.
Command
Registration
No.
Error code
(Hex 2Byte)
Tail Frame check
Frame (Ex.) ACK H10 X(x) H09 H1132 ETX BCC
ASCII value H06 H3130 H58(78) H3039 H31313332 H03
Item Description
BCC
When the command is lowercase(r), only one lower byte of the value resulted by adding 1 Byte each
to the ASCII values from NAK to ETX is converted into ASCII and added to BCC, and then sent.
Error code Hex and 2 bytes (ASCII code, 4 bytes) indicate error type. For the details, see 8.1.8 Error codes.
(5) Example
This example assumes that the direct variable %MW0 of station no.1 is registered for monitoring.
① PC request format (PC → GM7U main unit)
Registration format
Format name Header
Station
No.
Command
Registra
tion No.
Command
No. of
blocks
Device
length
Device
name
Tail
Frame
check
Frame (Ex.) ENQ H01 x H01 RSS H01 H04 %MW0 EOT BCC
ASCII value H05 H3031 H78 H3031 H525353 H3031 H3034 H41534446 H04
② For ACK response after execution of command (PC ← GM7U main unit)
Format name Header
Station
no.
Command Registration no. Tail Frame check
Frame (Ex.) ACK H01 x H01 ETX BCC
ASCII value H06 H3031 H78 H3031 H03
③ For NAK response after execution of command (PC ← GM7U main unit)
Format name Header Station Command Registration no. Error code Tail Frame check
Frame (Ex.) NAK H01 x H01 Error code (2) ETX BCC
ASCII value H15 H3031 H78 H3031 Error code (4) H03