User's Manual

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Protocol Sequence

A simple transmission protocol is used between the host controlling system and the

processor. The following control characters are used:

ASCII Hex Meaning

'ENQ' 05 The processor informs the host system that an event has occured.

– Data carrier in front of the read head, data are ready.

'DLE' 10 The host system queries the current status or a current event. This is

possible at any time.

'NAK' 15 Faulty or unrecognizable ASCII characters were received.

'STX' 02 Sent by the processor at the beginning of the data.

'ETX' 03 Sent at the end of the data.

BCC The block check follows 'ETX' at the end of the data and represents the

EXOR operation on the serially transmitted binary data from the data carrier

and the error number, i.e., the data between 'STX' and 'ETX' (see example).

SYN Software-Reset of the processor.

Controller mode

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Example: Output 40 bits of data carrier data to the host system

Data carrier data: 01hex 23hex 45hex 67hex 89hex

Sent characters: 'STX' 01234567890 'ETX' BCC

i.e., 12 characters are sent:

1. character Start of Text 02 (Hex)

2. - 11. characters Data carrier data (see above)

12. character Error number (see

12)

13. character End of Text 03 (Hex)

14. character Block Check Character (see below)

Block check formation: ASCII Hex binary

Data 0 30 0011 0000 EXOR

1 31 0011 0001 EXOR

2 32 0011 0010 EXOR

3 33 0011 0011 EXOR

4 34 0011 0100 EXOR

5 35 0011 0101 EXOR

6 36 0011 0110 EXOR

7 37 0011 0111 EXOR

8 38 0011 1000 EXOR

9 39 0011 1001 EXOR

0 30 0011 0000 EXOR

BCC 1 31 0011 0001

Controller mode

Protocol Sequence