PFIS State Transition Table
How to use this table: the rows are indexed by the state you are currently in. The columns are indexed by the final (not next) state that you want to end up in. For each (current,desired) state pair, the indexed table cell tells which transition to execute next, and what state that takes you to. Keep iterating until you end up in the desired state (you are done when you end up on the diagonal).
s1 s2 s3 s4 s5 s6
s1
-
+T1, S2 +T3, S3 +T2, S4 +T1, S2 +T3, S3
s2 -T1, S1
-
-T1, S1 -T1, S1 -T2, S5 -T1, S1
s3 -T3, S1 -T3, S1
-
-T3, S1 -T3, S1 +T2, S6
s4 -T2, S1 -T2, S1 -T2, S1
-
+T1, S5 +T3, S6
s5 -T2, S2 -T2, S2 -T2, S2 -T1, S4
-
-T1, S4
s6 -T2, S3 -T2, S3 -T2, S3 -T3, S4 -T3, S4
-

Example: Suppose you are in state S5 (Spectropolarimetry), and you want to be in state S3 (Fabry-Perot Imaging) for the next observation.

  1. (S5,S3) indexes the cell (-T2, S2). So execute transition -T2 (Remove waveplates). You are now in state S2 (Spectroscopy).
  2. (S2,S3) indexes the cell (-T1,S1). So execute transition -T1 (Articulate camera back to home). You are now in state S1 (Imaging).
  3. (S1,S3) indexes the cell (+T3,S3). So execute transition T3 (Insert etalons). You are now in state S3.
  4. (S3,S3) indexes the diagonal. You are done.