Matt Nelson has provided the following detailed breakdown of the exposure sequence:

1 -  ICC receives exposure request
2 -  ICC calculates and sets exposure time (SET cmd to controller)
3 -  Controller finishes loop in Continuous Reset, Processes command
     and replies to ICC.
4 -  ICC initiates exposure in controller
5 -  Controller finishes loop in Cont Reset, Breaks out of 
     loop to expose
6 -  Controller does full pixel by pixel reset of array
7 -  Controller Delays for reset settling
8 -  Read-1 reads are made 
9 -  Controller waits for calculated Integration time
10 - Controller waits for 400mS for Array outputs to stabilize
11 - Read-2 reads are made
12 - ICC finished scavenging last Read-2 read, builds frame and
     writes it to disc.
13 - ICC replies "done" to hub

Guesses about timing.

1-4 should be relatively fast.  The line loops in continuous reset are
quite quick so I would expect this sequence to finish in < 10mS

5-6 was never timed by me.  What I recall from the pixel clocks when I 
was developing the DSP code is that the reset pixel clock was running 
about 1/3 of a normal readout pixel clock.  So I'd guess ball park 
200-300 mSec for this

7 50mS

8 N*790mS

9 Exp Time - N*790ms

10 400mS

11 N*790mS

12-13 Unknown but fairly quick.  Most of the frame data are scavenged
   and averaged while the pixels are still being read.  it is just
   the recovery time of the last frame, subtraction of the Read1/2
   the writing of the frame to disc.  I'd estimate 100mS-200mS 
   nominal timing.  


Of course what is missing is the time required for the hub to cycle
back around to requesting the next in the frame series.  I'm certain
the APO staff would have a good estimate.  As a summary, the ICC
and controller are probably using up 250+50+400+150mS = 850mS of
time beyond the time spend during integration + readout.  So for
a rough estimate of instrument cycle time beyond the requested 
integration time  850+790*N mS should be close.