eVLBI Software Reference

Recording:

vsib_record:

Reads data from the vsib card are writes to the storage location (currently local disks).

Options:


-help
 Usage summary
-m <mode>
 Recording mode. Normally only use 2 for "16 bit" modes or 3 for "8 bit" modes. 8 bit corresponds to the normal recording rate of 256 Mbps.
-r <rate>
 recording rate (in Msamples/sec). Default is 32.
-t <time>
 Recording time. Either the time in seconds or total number of blocks to record (e.g. 10s is ten seconds, 100 is 100 blocks). Default is 3600 seconds (1 hour). Time in minutes or hours is also supported (e.g. 6h is six hours)
-s <time>
 Recording start time as fully qualified UT date. Multiple data forms are supported and include yyyy-mm-dd hh:mm:ss.s, yyyy-mm-ddThh:mm:ss.s, yyyymmddThhmmss.s
-w <bandwidth>
 Recording bandwidth. Defaults to 16 MHz. Should be a simple fraction of 16. (E.g 2, 4, 8)
-b <blocksize>
 Block size in bytes used for reading from vsib and writing to disk Default is 32000
-f <blocks>
 Amount of data to write per file. Either in seconds of number of blocks (e.g. 10s is ten seconds, 1000 is 1000 blocks). Default is 10 sec.
-o <filename>
 Filename prefix to use. The dayno and time (in seconds) will be added to the prefix to create a unique file name. Typically should use "Exper_ant", e.g. vt001d_Pa. Defaults to "test".
-c <mode>
 Use to record packed data, in which not all channels are recorded. Useful to reduce disk usage which the user data rate is < 256 Mbps. This should be a  4 character string, where 'x' signifies the channel is to be recorded and 'o'  or '0' means not to record the data. 'xxxx'  records all data.  'oxox' will record every second channel (so dual polarisation of a single frequency for a normal VSOP recording mode). 'ooox' will record only the first channel from the DAS. Current supported modes are oooo, ooox,  ooxx, oxox and xxxx (default).
-e <device>
 Name of vsib.o module device file to read from. Defaults to /dev/vsib.
-l
 Loop mode. Overwrites the data file eventually (??)
-v
 Verbose output


Examples:


vsib_record -o vt001d_Pa -t 7200s             # Normal recording
vsib_record -o vt001e_Pa -t 180m -c ooxx      # Only record first two channels
vsib_record -o vt001e_Pa -t 3h -w 4           # 4 MHz bandwidth recording
vsib_record -o vt001e_Pa -t 6h -s 2005-11-03T22:00:00 # Specify start time

Analysis

vsib_checker:

Checks output data files for consistency etc


-help
 Usage summary
-p/-pps
 Check datafile for 1PPS markers in the expected position (default)
-s/-stats
 Calculate sampler statistics for each data channel
-x/-count Check data from VSIC countdown mode for consistency
-search <pattern>
 Search for the give pattern (in hex) in the data files
-v/-vlba
 Data was recorded using VLBA (rather than AT sign/mag) convention
-r/-rate
 Data rate (in Msamples/sec) at which data was recorded. Default 32 Msps.
-b/-bits
 Number of bits per sample. Defaults to 2
-f/-fail
 Stop running after the first problem found in the data.
-V/-verbose
 Print more messages to the screen
-n/nbytes <n>
 Only analyze for first n bytes (rounded up to the size of the internal buffer, so
a value of 10 would be rounded up to 2e6).


Examples:


vsib_checker TESTFILE*                  # Look for 1PPS markers in a normal file
vsib_checker -stats -n 100 -vlba TESTVLBA* # Look at sampler stats, assuming VLBA stats
vsib_checker -x TESTDATA-*              # Check VSIC mode 6 data recorded at 8 bits
vsib_checker -x -b 16 TESTDATA-*        # Check VSIC mode 6 data recorded with 16 bits
vsib_checker -search FF00FF00FFOO DATA*

fauto

Computes the power spectrum of the data. Will integrate data from multiple data files


-help
 Usage summary
-v/-vlba
 Data was recorded using VLBA (rather than AT sign/mag) convention
-r/-rate
 Data rate (in Msamples/sec) at which data was recorded. Default 32 Msps.
-n/-nlags <n>
 Number of samples to use in FFT (number of spectral points is half this)
-C/-chan <n>
 Channels to analyse. Can be specified multiple times (e.g -C 1 -C 2). Defaults to 1
-b/-bits
 Number of bits per sample. Defaults to 2
-if1 <n>
 First channel in range to process
-if2 <n>
 Last channel in range to process. E.g. -if1 2 -if2 4 is equivalent to -c 2 -c 3 -c 4
-sp1 <n>
 First spectral point to plot (default 1)
-sp2 <n>
 Last spectral point to plot (default nlags/2)
-d/-device
 Pgplot device to use. E.g. /xs, plot.ps/cps plot.ps/ps plot.png/png
-nint <int>
 Rather than average entire data file, plot integrations of <int> seconds.
-pause
 Pause between plots if plotting sub integrations
-V/-verbose
 Print more messages to the screen
-n/nbytes <n>
 Only analyze for first n bytes (rounded up to the size of the internal buffer, so
a value of 10 would be rounded up to 2e6).


Examples:


fauto TESTFILE                  # Correlate all channels in a normal file
fauto -vlba TESTFILE            # Correlate data recorded in VLBA mode
fauto -if1 1 -if2 4 -nlags 2048 TESTFILE # Correlate first 4  channels
fauto -C 1 -C 3 -dev test.ps/ps TESTFILE # Write postscript for 2 channels

Realtime Fringe Checking

The documentation for the real time fringe checking software is available here



      

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