How to test the communications between SHARC-II and the antenna computer, which is necessary for chop-nod observations, 

as in SHARP.

Giles Novak, September 2013

SHARC-II and SHARP need not be installed or turned on.  The HWP is not used.  Only the SHARC-II computer in the lounge, 

the antenna computer, and the antenna itself are used.  The dome can be closed.

(1) walkabout to check for obstructions (you will be moving the telescope a little bit)

(2) start uip:

- open an xterm on kilauea

Open up an xterm on kilauea

Type "uip" at the prompt.  Then you should see a uip prompt (UIP>).

Type the following at the UIP prompt:

  pundit true (uip prompt should now be bold)

  inst sharc2

  cat sharccal

  cat sharp

pull the red emergency stop

point the telescope to an az and za that are very near to where it is currently already pointed, to avoid big moves

The telescope should switch from "IDLE" to "TRACKING"

(3) start up the SHARC-II processes that you will need by first opening up 2 new xterms on kilauea (or puuoo) as sharc, and then proceeding as follows:

(3a) Reset the sharcii DSP:

In window 1:

ssh sharc@sharcii

cd ~/DSP

sharcDSP

s2

status (should have 12 12's and 2 36's, but you will not see the 12 12s since this is not the normal startup)

status (check to make sure UT is updated)

quit

If the UT is not updating, try again a few times. If that still doesn't work, go to DSP help page:

http://www.submm.caltech.edu/~sharc/operating/manual.htm#DSP_reset

(3b) Start IRC:

In window 1:

cd ~/irc

sharcServer 

wait one minute (you should see the message `Startup Completed')

In window 2 (place on separate desktop, sharc on kilauea):

cd ~/irc

./sharcClient or ./sharcClientTest 

It should take only a minute to start, but in 2012 it required 7 minutes for it to start.  

When you get the warning about blocking unsafe components, click ``no'' (do not block).

In the sharcClient, click on "level hardware" 

(4) Try to take test Chop-Nod data (but the chopper need not be running for this test):

During actual SHARP observations we do a "coarse dither", but for this test we will just do a "single nod" so as to avoid attempting to move the half-wave plate. In the IRC Window, under "commanding", select "single nod".  Also in the IRC window, set the "Chop Throw (arcsec)" to 60, so that the nod is very small (just +/- 30 arcsec).  This way you will be making only very small telescope moves.

Now push the "start" button in the SHARC controls window to start the process.

Now look at the UIP screen and make sure that the chopper offsets are updating.  They should change back and forth between +30 and -30 over the course of the nod.  (The chopper offsets are called ``CHOP AZO'' and are toward the left side of the UIP screen.)  If the chopper offsets are not changing sign in this way, this means that the link between the antenna computer and the SHARC-II computer (in the lounge) is broken.  Hiro should be consulted.