dDSServer(1)              User Commands              dDSServer(1)



NAME
     dDSServer,     dDSControl,     dDSInit,     dDSSetBaselines,
     baselines.txt - DDS control programs

SYNOPSIS
     Executables live in /usr/home/rtm/bin on lablynx


DESCRIPTION
     "dDSServer"  is  an  RPC  server  which  controls  the   DDS
     hardware.    It runs as a background process on the computer
     housing the DDS hardware (currently lablynx).   It  can  set
     the  DDS synthesizers to output constant frequencies, or can
     change the frequency and phase at 100 Hz  to  stop  fringes.
     It  can  superpose phase changes on top of the normal output
     signal, if phase changes are requested by RPC  calls.    The
     RPC     interface     is     defined     in     the     file
     /usr/home/rtm/dDS/rpcFiles/dDS.x on lablynx.    Some  status
     information is printed as it changes the settings of the DDS
     hardware.   Because the process is automatically started  at
     boot  time,  this  status information normally is printed on
     the lablynx console.   If you wish to see this status infor-
     mation,  you  should kill the process running dDSServer, and
     restart it from your terminal, in the background.

     The first rpc call to "dDSServer" causes  it  to  initialize
     its  software  state.   The hardware state may or may not be
     modified by the first call, depending  on  what  command  is
     specified  in  the  RPC  call.   Separating the software and
     hardware initialization allows the server to process a  com-
     mand that disables hardware access, and this command in turn
     allows the server to  be  run  on  a  computer  without  DDS
     hardware.   This feature is useful for code development.

     Before  "dDSServer"  is  run,   the   environment   variable
     DDS_CONFIGFILES  must  be  defined  to  point to a directory
     holding a baselines file called baselines.txt .   The  base-
     line information is read from that file.

     "dDSControl" is  a  menu  driven  interactive  program  that
     allows  you  to send RPC requests to the DDS server.   There
     is a copy on lablynx, but it could be run on  any  computer.
     This program allows you to do several DDS operations includ-
     ing:

     Reset the DDS frequencies to the nominal value of 9 MHz (109
     after mixing)

     Start fringe tracking for a new source

     Specify a new observing frequency




SunOS 5.5           Last change: 1998 Dec. 2                    1






dDSServer(1)              User Commands              dDSServer(1)



     Print the current DDS status (frequency, phase HA etc).

     "dDSInit" merely sends an RPC request to the DDS server that
     causes  the  server  to initialize the software and hardware
     state to the nominal values.  This program is  run  at  boot
     time,  and  probably  is of little interest to users because
     "dDSControl" provides this  same  functionality  in  a  menu
     driven program.

     "dDSSetBaselines" reads the file baselines.txt, and issues a
     command to the DDS server telling it the new baseline param-
     eters.   Before running this program, the environment  vari-
     able  DDS_CONFIGFILES must be defined to point to the direc-
     tory where baselines.txt resides.

     "baselines.txt is a plain ASCII file  containing  the  base-
     lines for all antennas in the SMA array.   There is one line
     per antenna, and the program expects to see 10 lines of data
     (8  SMA  antennas  +  CSO  and JCMT).  Each line must have 3
     numbers, the X, Y  and  Z  coordinates  of  the  antenna  in
     meters.   The coordinate system is shown in figure 4.6, page
     87 of Thompson, Moran and Swenson.  This file is just a tem-
     porary  kludge  -  the  final system will have several files
     which taken together will specify the baselines.

KNOWN BUGS
        The program dDSServer needs  to  know  which  receiver  -
     antenna  combinations  are  really operational.   Ultimately
     there will be array configuration files on hal  that  deter-
     mine this, and the information will be sent to dDSServer via
     RPC.   Right now, the program is hardcoded  to  assume  that
     only antennas 2 and 3 exist, and only receiver 1 is active.

        Doppler tracking has not been implemented.


ENVIRONMENT
     The  programs  dDSServer  and  dDSSetBaselines  expect   the
     environment  variable DDS_CONFIGFILES to point to the direc-
     tory where the file baselines.txt resides.


RESPONSIBLE
     Raoul Taco Machilvich
     rtm@dolson.harvard.edu
     617 495-7330
     617 873-0877


ACKNOWLEDGMENTS
     The active guts of this program which controls the  hardware
     was stolen from a program written by John Test.



SunOS 5.5           Last change: 1998 Dec. 2                    2