Quick introduction to the database.dat file

DCSS requires a memory mapped file containing the list of beamline devices and current state of these devices. This file is currently always named database.dat. Refer to maintaining database.dat for a complete reference on how to create and use this file. If you are just getting started and want to play with a simulation, an example database is available in text format. To use this file, follow the these steps:

1. Copy an example dump file (i.e ending with .dat) from the dcsconfig/data directory.

   cp ./dcsconfig/BL9-1.dat ./dcss/linux

2. Using a text editor, edit the DHS entries to match the hostnames of the computers running DHS's on the new beam line. For example, the third line of a DHS entry may need to change to reflect the name of a DHS running on a different computer. DCSS will reject a DHS connection from a hardware host that is coming from a host different from what is specified in this file.

   Example:

   simDhs
   3
   localhost 2
   

3. Generate the memory map file (i.e. database.dat) using the ./dcss -r command.

   Note: This step will completely overwrite an existing database.dat file, which usually contains current motor positions.

      cd dcss/linux
      ./dcss -r example_bl111sim_dump.txt
   
      ....<OUTPUT REMOVED>.........
   
      A total of 171 devices were read in from the dump file.