2 ] Control Characters - Denso BHT-8000 User Manual

[ 2 ] Control Characters

The control characters are classified into two groups: transmission control characters and text control
characters.
(1) Transmission control characters
The transmission control characters listed below are used to compose transmission control sequences
in phases 1 through 3.
Symbol Value
EOT 04h
ENQ 05h
ACK 06h
NAK 15h
!
Transparency
The BHT uses the non-transparent mode which handles the control characters and codes (e.g., STX,
ETX, and SOH) as starting or ending markers and does not allow them to be transmitted as normal data
in the transmission texts.
(2) Text control characters
The text control characters are used to format transmission texts. In the BHT-protocol, they include the
following headers and a terminator.
Symbol Value
SOH 01h
STX 02h
ETX 03h
You may designate headers and a terminator with the protocol functions in BHTBASIC. If you designate
none of them in a user program, the BHT may apply those as listed above. Refer to the "BHT-BASIC
Programmer's Manual."
Meaning
End Of Transmission
Enquiry
Acknowledge
Negative Acknowledge
Meaning
Start Of Heading
Start Of Text
End Of Text
Chapter 3 Communications Operations of BHT
Releases a data link
(Phase 3).
Requests abort of transmission
(Phase 2).
Requests establishment of a data link
(Phase 1).
Prompts the receiver to respond to the sent text
(Phase 2).
Acknowledgment response to ENQ
(Phase 1).
Acknowledgment response to text
(Phase 2).
Acknowledgment response to EOT
(Phase 3).
Negative acknowledgment response to ENQ
(Phase 1).
Negative acknowledgment response to text
(Phase 2).
Indicates the start of heading text (Phase 2).
Indicates the start of data text (Phase 2).
Indicates the end of data text (Phase 2).
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Function
Function