Receivers/GEBMerge/GEBsort

gtReceiver4

To take data with the DGS DAQ, you must start a gtReceiver4 for each of the IOC that are collecting data. This is usually done from a script which starts all the necessary receivers and controls the run number.

To get the gtReceiver4 receiver do the following

• cd to where you want to compile the gtReceiver4

• wget http://www.phy.anl.gov/gretina/gtreceiver/tar.tgz

• tar -zxvf tar.tgz

• make clean

• make

That should generate the gtReceiver4 program. Here is an example how to run the program:

 gtReceiver4 ioc1 data_run_001.gtd 2000000000

Here we are asking gtReceiver4 to acquire data from ioc1 and put the data in the file data_run_001.gtd. That will not actually be one file as gtReceiver4 splits the data stream into a file for each of the digitizers the IOC serves. That makes it easier to merge and time order the DGS data later. 2000000000 specifies the max size of the files, here keeping them under 2GBytes, so they can be read on all machines.

The gtReceiver4 program writes data out in the GRETINA GEBheader/Payload form, with a data ID of GEB_TYPE_DGS=14. This means that the GT GEBMerge and GEBSort programs can be used for DGS data as well as GT data

GEBMerge

GEBMerge allows you to merge all the files that the instances of the gtReceiver4 created during your run. In addition to merging the data, GEBMerge also orders the merged data based on the timestamps in the GEB header. This merger and time stamp ordering program will work on all kinds of data, as long as the data are in the GT GEB header/Payload format, including data taken with the gtReceiver4 receiver.

You will use the program as

 GEBMerge GEBMerge.chat outfile     file1  file2  file3  file4 .....

where GEBMerge.chat is the file that contains parameters for the merging, such as the buffer size to use. The merged data will be written to outfile and file1 file2 file3 file4 ..... is the list of files to merge.

GEBMerge is part of the GEBSort package. See the link below for how to get the GEBSort package. gtReceiver4 is specific to DGS; but the GEBSort package can handle many other kinds of data as well.

GEBSort

GEBSort is a rather general purpose ROOT sorter, that, in addition to being able to read GRETINA data, also can read DGS data acquired by gtReceiver4. This sorter is documented under the GRETINA wiki pages

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