FrWrite writes frames containing a user-defined subset of the channels from the input frames. The input data source may be either an online shared memory partition or one or more frame files. The data are written to one or more frame files, the names of which may include a time stamp generated from the GPS time of the first frame in the file. The list of channels to be written is specified in an optional configuration file. If no configuration file is specified, all available channels are written.

Note: At present, no pre-processing is performed on the data. Filtering, decimation and time deskewing are expected to be added at some time in the future. (January 27, 2000).

The FrWrite Configuration File

The FrWrite configuration file specifies which channels are to be written to the output file. Each line of the configuration file specifies a single channel name. Comment lines may be interspersed throughout the file and must have a '' in the first column. A single error message is generated if a requested channel doesn't exist in a given frame, although a message will be printed each time a channel is not found if the debug flag is non-zero.

Running FrWrite

The syntax of the FrWrite command is as follows:

FrWrite [-partition <part-name>] [-infile <file>] [-debug <dbg-level>] \
        [-cfile <conf-file>] [-nframe <nFrame>] [-repeat <nFile>] [+toc] \
        [-ofile <out-file>] [-sequence <nSeq>] [-trigger <osc-file>] \
	[-resize <nSec>]
     

Where the arguments have the following meaning:

<part-name>	Shared memory partition with data to be read.
<file>	Input frame file (exclusive of <part-name>).
<dbg-level>	Debug level [0].
<conf-file>	Configuration file name [].
<nFrame>	Number of frames to write in each file [1].
<nFile>	The number of files to be written [1].
<out-file>	Output file template [FrWrite-%Y.%m.%d-%H.%N.%S.F]
<nSeq>	The number of output files in a sequence [0].
<osc-file>	Trigger definition file [].
<nSec>	New output frame size [0]

The partition name is mutually exclusive with the input frame file name. If both are specified, data are read from the specified shared memory partition. Multiple input files may be specified either with several "-infile <file>" arguments or with wild-cards (e.g. "-infile '*.F' "). The debug level defaults to 0 (no debug messages). Any other value for <dbg-level> will cause debugging messages to be printed to cout. The <out-file> argument is treated as a template for generating file names. The name is generated with <A HREF="Sand/TimeStr.html">TimeStr() </A>using the template and the GPS start-time of the first frame as arguments. You can thus include the GPS time in seconds by using a file name template of e.g. "MyFrame-%s.F". If &lt;nFile> is zero, FrWrite will continue to write frame files until it is terminated with a ctrl/c or a kill command. Output files may be divided into sequences of <nSeq> files. This is most useful for limiting the number of files in a single directory. The sequence number may be incorporated into the output file name with a "%q" token. The <osc-file> defines an optional condition that the input frame must satisfy for the data to be written to the output. the +toc argument indicates that a table of contents is to be written at the end of each output frame file.

Author:

J.Zweizig

Version:

2.2; Modified September 19, 2000