Date: Sat, 17 Oct 2009 14:46:26 -0600
From: Dan Long
Subject: Re: 2.5m obslog 20091016 (MJD 55121) Imager and IDs
>                        APACHE POINT OBSERVATORY SDSS 2.5M
>
>                                  OBSERVING LOG
>                             Friday October 16, 2009
>
>                                   (MJD 55121)
>
>---=== OBSERVING TEAM ===---
>
>         Audrey Simmons
>         Steph Snedden
>
>         Kyle Dawson (U ofU)
>         Alex Kim (LBL)
>
>.
.
.
.
>Afternoon:
>----------
>
>We ran into some problems mounting the imager, and wound up calling Dan.
>    1) saddle latch 1 LED did not go on when latched once, but the latch itself
>moved. On a subsequent try, it was okay.
>    2) The instrument ID switches said cart 5, when we really had the imager
>on. We had to use the manual side of the lift control (we called Dan first).
>
    Today Bob took a look at the saddle latches and also successfully
mounted and dismounted the imager 3 times in a row using auto mode.
Maybe there is some sort of tidal effect that only happens when the
sun is at or near the western horizon, especially since last night's
mounting problem is not the same as that of the previous night? :).
In any case here is hoping you have more imaging opportunities
tonight, and no problems mounting the imager.
    Regarding instrument ID, I have sent around the formula for
translating the tpm instrument ID values into the new PLC scheme (day
log from 22-sep-2009) until the new mcp is installed, and I repeat
that section here and add a translation table as well.
   If you look at the TPM, you will see the three ID switch blocks
indicating some cartridge (or engcam). In the new scheme, each block
has four possible configurations to represent the two bits
(redundantly indicated across 4 switches).  It will register as 5, 6,
9, or engcam(10).
engcam == binary 00
cart 9 == binary 01
cart 6 == binary 10
cart 5 == binary 11
If you concatenate blocks 1, 2, and 3, you get the cartridge number.
Example:
    The tpm reads
Block 1:  engcam     --->   00
Block 2:  cart 6     --->   10
Block 3:  cart 5     --->   11
Concatenating 1:2:3   --->  001011  -->  Decimal 11
Below is a translation table for the instruments instead of the formula.
Instrument     Block 1        Block 2          Block 3
Empty      0000 => disc     0000 => disc     0000 => disc
Cart 1     0101 => engcam   0101 => engcam   0110 => cart 9
Cart 2     0101 => engcam   0101 => engcam   1001 => cart 6
Cart 3     0101 => engcam   0101 => engcam   1010 => cart 5
Cart 4     0101 => engcam   0110 => cart 9   0101 => engcam
Cart 5     0101 => engcam   0110 => cart 9   0110 => cart 9
Cart 6     0101 => engcam   0110 => cart 9   1001 => cart 6
Cart 7     0101 => engcam   0110 => cart 9   1010 => cart 5
Cart 8     0101 => engcam   1001 => cart 6   0101 => engcam
Cart 9     0101 => engcam   1001 => cart 6   0110 => cart 9
Cart 10    0101 => engcam   1001 => cart 6   1001 => cart 6
Cart 11    0101 => engcam   1001 => cart 6   1010 => cart 5
Cart 12    0101 => engcam   1010 => cart 5   0101 => engcam
Cart 13    0101 => engcam   1010 => cart 5   0110 => cart 9
Cart 14    0101 => engcam   1010 => cart 5   1001 => cart 6
Cart 15    0101 => engcam   1010 => cart 5   1010 => cart 5
Cart 16    0110 => cart 9   0101 => engcam   0101 => engcam
Cart 17    0110 => cart 9   0101 => engcam   0110 => cart 9
Engcam     1010 => cart 5   1010 => cart 5   1001 => cart 6
Imager     1010 => cart 5   1010 => cart 5   1010 => cart 5
				Cheers,
				  Dan