DAQSYS
(Some )Description of the data acquisition of the EUROFLUX system at
Sorø.
usage
- Start the programme with startram.bat
- press F1
to see the data screen
- No
is the number in the list.txt file
- Signal
Text is the variable name
- Signal
Type is the variable type
- Bd is : I don't know
- Addr
is the base addres of the data source (AD converter or com: port)
- Ch
is the Channel for this data source (e.g. PAR sensors ar connected to a
DAU without multiplexer, the channeles for connectors 1, 2, 3, 4, 5, 6,
7, 8 are 1, 17 33, 49, 65, 81, 97, 113)
- Gain, Offset:
DaqSys uses a fixed linear conversion from an INT (I) that is retrieved from an data
source address to V(olt). Th ecalibrated value (Vcal) is then calculated
as :
Vcal
=
Fs(
aI+
b)
(1)
Gain=
Fsa
(2)
Offset=
Fsb
(3)
with typical values for
a = 0.001221 and
b =-2.5. The values of
a,
b,
Gain and
Offset are given in the
list.txt
file.
- Blocking factor. A factor
the base frequency is mutilplied with in order to give the frequency
the data are averaged. A usual base frequency os 20 Hz. The chanbel 1
(sin) is configured with a blocking frequency 5. This means all 20 Hz
values will be averaged to give a frequency of 4 Hz (averaging time
0.25 s). These data are (oversampled) raw data that will be further
used to calculate statistics for the run (30 minute data).
- Save: only the first two
digits of this string have a meaning.
1st two digits
|
save_set keyword in list.txt
|
fast data saved |
00
|
stats
|
NO
|
01
|
cal,stats
|
YES
|
- Switch between displaying run and block statistics press ASK MIKE?
- Stop the programme:
- CTRL+W
(to stap watchdog)
- CTRL+C
(to stop DaqSys)
configuration
DaqSys is configured with (only) one file list.txt. It is currently
located in the directory \daq\data.
The fil contains comments (beginning with ';') and configuration
information (key_word=value).
- A series of channles (usually those that are connected to acommon
data source unit, i.e. AD-converter card or com port, might start with
the definition of default settings .
this begins with @default
and it's followed by some statements including e.g.
data_type=analogue
board_type=AD08
base_address=16#308
mode=0
gain=0.002442
offset=-4.999
units=V
save_set=stats
blocking=5
(for explanations, see
remarks for the variables displayed data screen
or ASK MIKE)
hardware
The Euroflux system is connected to various data acquisition units
(DAU) and serial connectors (COM ports)
.
Example: DAU for PAR sensors.
Example of various connector cards: COM ports and connectors to DAUs
Example: DAU for temperature measurements
Example: DAU for Sunshine sensor (BF2) and UVB sensor
Mike
(+45 4677 5008)
