Intro:

scramPuppi

    Program to run on guppimaster reading "scramNet" multicast packets and then loading the information  into guppi shared memory.

• scramnet "multicast" packets:
  
• Some of the online datataking is connected via "scramnet" which is a fiber based shared memory system.
• The vme crates connected are: cor, da, pnt .
  
• the solaris workstations observer and control are also connected.
• The multiscram program on observer reads the scramnet shared memory once a second and multicasts this info onto aonet.
• Other programs running on computers not connected to the scramnet shared memory also multicast info about their state. These packets are also refered to as scramnet packets even though they don't pass through the scramnet shared memory:
• observer2: the cima executive
• wappN : the wapps also broadcast their state.
• the puppi (or guppi..) is the 800 MHz coherent dedispersion pulsar processor. 
• It is controlled by keyword values stored in "guppi status" shared memory on puppimaster.
• scramPuppi attaches to  this shared memory and  updates the variables  whose state is defined in the scramnet packets.

Usage: scramPuppi {-d} {-t}

• no options:
• connect to guppi_status shared memory,  and start updating shared memory with info from multicast packets.
  
• -d   run in debug mode.
• do not attach to guppi shared memory
• do not become a daemon. All output goes to stdout.
• Output program info every 1 second.
• -t  run in debug mode. Same as -d except output timing info for when the multicast packets arrive.

Examples:

• Normal run:
• /home/gpu/phil/scramPuppi
• kill pid whenever you want
• scramPuppi -d  
  
•    telescope:            ARECIBO 305m      project_id:                   p2702
      Observer:                      JD         fd_poln:                     LIN
        source:              J0337+1715        pol_type:                       
      frontend:                     lbw      rcvr_polns:                       2
       backend:                   PUPPI            npol:                       0
          fctr:             1380.000000         scanlen:                0.000000
            BW:             -800.000000      scanNumber:                       0
      cal_mode:                             wappRunning:                       0
    cal_dcydle:                0.000000       beam_FWHM:                0.000000
     cal_phase:                0.000000         ObsMode:                       
      cal_freq:                0.000000      track_mode:                       
        reqRaJ:              03:37:43.8       feed_mode:                       
       reqDecJ:              17:15:15.0     fd_angleReq:                0.000000
      req_glat:              -30.039521         pos_ang:                0.000000
      req_glon:              169.989558           ant_x:          2390486.900000
        tel_az:               65.150691           ant_y:         -5564731.440000
        tel_za:                2.491296           ant_z:          1994720.450000
  
  
• 
  

Program flow:

• On startup (assuming -d and/or -t not set).
  
• become a daemon
• create /tmp/scramPuppi.lok to use as a lock file so only one copy at a time can run.
  
• set message output to syslog
• setup a signal handler to catch signals (so we can cleanup on exit)
• Set some keyword values that don't change
• attach to guppi_status  shared  memory
• Program loop:
• input scramnet packet.
• If it is one of the packets that we want,store the info we need.
• Compute variables that use info from more than one packet.
• if more than 1 second has passed since last update, update shared memory
• if the wapprun variable changed  update immediately. This could be used to start,stop puppi.
• Sending a kill signal to scramPuppi will cause it to go through it's cleanup routine and exit
• Cleanup routine:
• remove lock file
• unlock semaphore if holding it
• detach from gupp_status shared memory

Variables set by scramPuppi:

    The table below lists the guppi status variable that are modified by scramPuppi. All of the updates are done in the routine updateShm(). If you want to
disable a particular keyword, value, just comment out the hputX line in updateShm.

Possible problems:

• ra,dec are requested not actual. If the telescope stops or falls behind then they will not be where we are pointed.
• The az,za always contain the physical position of the the telescope.
• we could back compute ra,dec from az,za if it is necessary.
• Cals:
• the above only knows about a winking cal or no cal.
• Turning the cal on constantly gives CAL_DCYC = 0.
• Timing:
• When the scramNet packets arrive, the shared memory will be updated.
• If there is a delay in moving the info from guppi_status shm into the fits headers, then they may  be out of sync for awhile.
• I don't know whether the fits writing code continually updates all the info from shared memory, or just things that they assume will change rapidly.
• You could use the variable wappRunning and wappSEcsToRun to start and stop puppi.
• Integration:
• scramPuppi runs till aborted. It will keep the shared memory attached the entire time.
• If you want to clear out and delete the pointer to shm you should probably kill scramPuppi first.
  

File locations:

• source directory:: /share/megs/phil/svn/aosoft/src/puppi
• This is extracted from the svn repository
• scramPuppi.c  c code
• Makefile     to make program on puppimaster
• puppimaster:
• /home/gpu/phil
  
• Libraries
• -lpntXform, -lphil
  
• I've put these on puppimaster /home/gpu/phil/lib
• /tmp/scramPuppi.lok - lock file created by scramPuppi