CAMAC Progress Report

                    Week Ending: November 09, 2001
                               Week: 41


Tom Folkers:
     1. Various administration activities left me with little time to 
        work on CAMAC issues.

Tom Sargent:
     1. Analyzed the recorded position data from the last test run at 
        the SMT and compared it to the performance of the old VAX 
        system.  I concluded that the new servo program needs to close 
        the loop more tightly.  It will break all motions (except 
        tracking) into 3 phases:
          1. Ramp up to maximum speed (4000 arcsec/sec.)
          2. Steady motion at maximum speed.
          3. Ramp down to a position just before the target object and 
             terminating  at a velocity chosen to make the tracking 
             algorithm quickly lock on.  (Smaller motions will be 
             missing the middle phase.)
     2. The actual V(t) curve will be tightly constrained to match the 
        pre-computed one.  Accumulated position errors will be 
        corrected well before the end of the track. So, this is 
        expected to place the telescope right on target quickly.
     3. I removed the velocity calculation from the DSP processor and 
        moved it into the servo program.  I changed the velocity 
        algorithm to be one that fits a parabola to the last 10 
        reported positions and then evaluates the derivative of that 
        parabola at the end point. Comparing this and the old method 
        using recorded data, this appears to produce a smoother  
        observed V(t) curve with higher highs and lower lows. It 
        clearly has better frequency response than the old 
        deltaX/deltaT method. Better accuracy in velocity measurement 
        is needed by the new velocity servo algorithm.
     4. The software to break any telescope movement into the 3 phases 
        described above and provide a pre-computed V(t) and X(t) path 
        was written and tested. It handles large and small motions in 
        any direction.

Pete Hubbard:
     1. Reworking encoder amplifier boards. The 2 spare boards that 
        were from the SMT are different from the ones that are in the 
        new electronics. The first board that I looked at has some 
        traces that have to be replaced along with the Cos input op-
        amp had to be replaced. The second I modified to match the 
        changes made on previous boards.
     2. Fixed the AZ amp board that was used last trip to the SMT. 
        It's encoder operating Led was not lit when the Az encoder was 
        plugged in.

Dave Ashby:
     1. No Report.