Chapter8 Communication Function
8-5
8.1.3 Frame Structure
1) Base Format
(1) Request frame(external communication device
ᆌ
K7 base unit)
(Max. 256 Bytes)
Header
(ENQ)
Station
number
Command
Command
type
Structurized data area
Tail
(EOT)
Frame check
(BCC)
(2) ACK Response frame (K7 base unit
ᆌ
external communication device, when receiving data
normally)
( max. 256 Bytes)
Header
(ACK)
Station
number
Command
Command
type
Structurized data area or null code
Tail
(ETX)
Frame check
(BCC)
(3) NAK Response frame (K7 base unit
ᆌ
external communication device, when receiving data
abnormally)
( max. 256 Bytes)
Header
(NAK)
Station
Command
Command
type
Error code (ASCII 4 Byte)
Tail
(ETX)
Frame check
(BCC)
Remark
1) Used control codes are as follows. Be familiar with the following control codes. Because they are importantly
used for communication.
[Control codes]
Codes
Hex value
Name
Contents
ENQ
H05
Enquire
Request frame initial code
ACK
H06
Acknowledge
ACK response frame initial code
NAK
H15
Not Acknowledge
NAK response frame initial code
EOT
H04
End of Text
Request frame ending ASCII code
ETX
H03
End Text
Response frame ending ASCII code
