Denso BHT-7500W, BHT-7500S Control Characters, Transmission control characters, Transparency

Chapter 3. Communications Operations of the BHT

[ 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	Meaning	Function
EOT	04h	End Of Transmission	Releases a data link (Phase 3).
			Requests abort of transmission
			(Phase 2).
ENQ	05h	Enquiry	Requests establishment of a data link
			(Phase 1).
			Prompts the receiver to respond to
			the sent text (Phase 2).
ACK	06h	Acknowledge	Acknowledgment response to ENQ
			(Phase 1).
			Acknowledgment response to text
			(Phase 2).
			Acknowledgment response to EOT
			(Phase 3).
NAK	15h	Negative Acknowledge	Negative acknowledgment response
			to ENQ (Phase 1).

Negative acknowledgment response to text (Phase 2).

■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.

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