FingerVein Online
Installation and Programming Manual
Page
33 of 69
character 0x03
To speed up data transmission to the serial ports (e.g. for biometric data transmission),
the UDP frames have the Extra Data field that encodes the end of the frame:
<OPC><NA><ARG><CRC><ETB>[Length][Data]<CRC>
<ETB>
:
Extra Data start indicator (
End Transmission Block
, ASCII
$17
).
[Length]
: [ 4 char: ] This parameter indicates the number of bytes that
are encoded in the Extra Data data field. It is a 16 bit value
expressed by four hexadecimal characters representing a hex-
adecimal four-digit value. The maximum supported length is
912 .
[Data]
:
This contains the Extra Data information. This field will be
made up by
[Length]
pairs of hexadecimal ASCII charac-
ters representing each of the
[Length]
information bytes.
<CRC>:
[ 1 byte ] This field contains a byte value resulting from add-
ing all the ASCII values of
[Length]
and
[Data] in mod-
ule 255 (
<ETB> is not included). Expressed by two
hexadecimal ASCII characters.
9.2. Bio-OCX UDP frame format
If the FingerVein Online electronics 5500 IP port is used, the frames should be in the
following format:
<OPC><NA><ARG><CRC>
Where:
<OPC>:
[ 2 char ] This parameter indicates the meaning of the frame
and enables you to interpret the data it contains. It is a binary
byte.
<NA>:
[ 4 char: ] This parameter indicates the number of bytes that
are encoded in the data field. It is a 16 bit value expressed in
binary format.
<ARG>:
[ 2 x NA char ] This contains the frame information. This
field will be made up of <NO> bytes with information
directly encoded in binary format.
<CRC>:
[ 2 char ] This field contains a byte value resulting from add-
ing the rest of the bytes of the frame in module 255 except for
<CRC>.
