LS Industrial Systems GLOFA G7M-DR20U/DC - Page 244

Chapter 8. Communication Functions
8-18
(4) GM7U main unit response format (NAK response)
Format name Header
Station
No.
Command
Command
type
Error code
(HEX 2 byte)
Tail Frame check
Frame (Ex.) ENQ H10 W(w) SB H1132 EOT BCC
ASCII value H05 H3130 H57(77) H5342 H31313332 H03
Item Description
Frame check
(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 HAA15056 is written in %QD0.0.0 at station no.1
① PC request format (PC → GM7U main unit)
Format
name
Header
Station
No.
Command
Command
type
Variable
length
Variable
name
No. of
data
Data
Tail
Frame
check
Frame
(Ex.)
ENQ H01
w SB H08 %QD0.0.0 H01 HAA15056F EOT BCC
ASCII
value
H05 H3031 H77 H5342
H3038
H254442302
E302E30
H3031
H41413135
30353646
H04
② For ACK response after execution of command (PC ← GM7U main unit)
Format name Header Station No. Command Command type Tail Frame check
Frame (Ex.) ACK H01 W SB ETX BCC
ASCII value H06 H3031 H77 H5342 H03
③ For NAK response after execution of command (PC ← GM7U main unit)
Format name Header Station No. Command Command type Error code Tail Frame check
Frame (Ex.) NAK 01 W SB Error code (2) ETX BCC
ASCII value H15 H3031 H77 H5342 Error code (4) H03