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10 Advanced Parameters and Commands
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The character sequence is divided into the following parts:
N
nnnnnnnn
n
= file size in bytes – 1. Creating a file of size 0 is not specified.
S
ttmm
t
= file type (any between „
01
“ and „
FE
“), m = transmit mode (always „
00
“).
[PAUSE]
To prevent an overflow of the input buffer a pause of at least one second has to be
maintained at this point. The file system needs time to open the file and delete the data
of an eventually existing file.
D
dddddd… n+1
data bytes in ASCII hexadecimal representation. (two characters 0…9,A…F per
byte).
If an error occurs during transmission, the operation will instantly be aborted. The camera module
sends a “?” character as error mark. Already transmitted data bytes will stay stored in the file, meaning
that the first part of the file may still exist after abort. The sender should regularly check for reception
of the “?” while transmitting large files to efficiently recognize the error situation. This allows the
sender to stop the transmission. As soon as the module outputs its command prompt the sender may
retry the transmission. If the transmission fails several times, the flash chip may be full or there is an
error in the hardware.
Warning: Do not switch off the camera during file writing operation (e.g. command
d=<p8>
or
Q=<p8>
) until the host received the command prompt character “>”. Doing so will very likely corrupt
the file system. In this case the camera has to be returned to VDS Vosskühler for system recovery.
To retrieve (view) a file, the command
v=<p8>
may be used. This command directly outputs the data
bytes of the specified file to the serial interface (not in ASCII hexadecimal notation as with
Q=<p8>
).
The above mentioned example would produce following output:
>v=10
Testtext
>
Because this example uses an ASCII text file, the data can be displayed correctly in a terminal
window. For binary data this is not the case. Be careful with large files: outputting them may take a
while.
For an easy access to the file system VDS Vosskühlers also offers an Windows application (“File
manager”) that can be used to upload files. This is also included in the “AcquireControl” application
and can be started by command
[CTRL+F]
.
VDS Vosskühler GmbH
IRC-320