User's Manual
Table Of Contents
- 1 About this Manual
- 2 Safety Regulations
- 3 Product Description
- 4 Design and Function
- 5 Mounting and Installation
- 6 Start-Up
- 7 System mode
- 8 Description of the Subpartyline
- 9 Packaging / Returns
- 10 Disposal
- 11 Index
Manual B-Net® 91 04 Description of the Subpartyline
12/2008 © Kaba GmbH 43
8.3 Control Characters and Control Sequences
Remark
Control characters are displayed in angle brackets, e.g. ESC (1B
hex) as <ESC>. An
underline character “_” is used as blank (2Ø
hex).
In the following examples “0” is used as group address (GID) and “1” as device
address (DID).
The following characters and sequences are used as control characters:
Control characters/
sequence
Meaning
<STX>
STX Start of Text Beginning of the text
<ETX>
ETX End of Text End of the text
<EOT>
EOT End of transmission End of the transmission
<NAK>
NAK Negative
Acknowledgement
Negative feedback
<ENQ>
ENQ Enquiry Enquiry
<DLE> 0
ACK0 Acknowledgement 0
<DLE> 1
ACK1 Acknowledgement 1
Alternating positive feedback
<DLE> <
RVI Reverse Interrupt Reverse Interrupt
ACK0, ACK1 and RVI consist of two characters. The second character (0, 1, <)
added to the control character DLE defines which of the three control characters is
meant.
The handshake in the BPA is effected via control characters and control
sequences.
The control sequences are:
<EOT> @ @ A A <ENQ>
Transmit polling
<EOT> ´ ´ A A <ENQ>
Receive polling
These control sequences are used to notify the subterminal whether it has to send
existing data records, or if it has to receive a data record. For receive and transmit
polling, the two addresses are sent twice in order to have a verification possibility.
<EOT> GID GID DID DID <ENQ>
8.4 Data Records
Data records are marked up by the control characters STX (beginning) and ETX
(end). The ETX is followed by an LRC - a check character which is calculated by
exclusive OR of the data and the ETX control character. The STX is not considered
in this calculation.
<STX> Data <ETX> <LRC>