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 |
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DLE EOT | 1004h | End Of Transmission | Releases a data link (Phase 3). |
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| Requests abort of transmission |
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| (Phase 2). |
DLE ENQ | 1005h | Enquiry | Requests establishment of a data link |
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| (Phase 1). |
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| Prompts the receiver to respond to |
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| the sent text (Phase 2). |
DLE ACK | 1006h | Acknowledge | Acknowledgment response to DLE |
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| ENQ (Phase 1). |
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| Acknowledgment response to text |
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| (Phase 2). |
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| Acknowledgment response to DLE |
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| EOT (Phase 3). |
DLE NAK | 1015h | Negative Acknowledge | Negative acknowledgment response |
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| to DLE ENQ (Phase 1). |
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| Negative acknowledgment response |
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| to text (Phase 2). |
WACK | 103Bh | Wait for Acknowledge | Requests suspension of data recep- |
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| tion during erasure of the flash |
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| memory. |
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■Transparency
The BHT uses the transparent mode which allows the control characters and codes (e.g., STX, ETX, SOH, and DLE) to be transmitted as normal data in the transmis- sion texts.
To transmit a DLE as normal data, type DLE DLE per DLE.
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