Binning and RTS2

Recently we've been having some troubles getting binning to work under RTS2 with our Alta CCD. Binning is a technique that can be used to speed up the dead time spent reading an image from the CCD - something that is very useful for the kind of high frame rate we wish to achieve with our system.

During testing a month or two ago we found that our Alta U47 would become unresponsive after setting the binning to 2x2 in the RTS2 monitor. The camera essentially stops responding to commands and needs to be power cycled to come back to life. I've been debugging the Apogee drivers forked in the RTS2 codebase for a while until I stumbled onto a quick fix: simply set the binning in the CCD script instead of directly in the monitor! I'm not sure why I didn't try this earlier. Here's an example:

rts2-scriptexec -d C0 -s 'binning=1 E 2 E 2'

This script sets the binning and then exposes twice for 2 seconds each. The readout time is about 0.5-0.8 seconds for each frame. Note that 1x1 binning is actually selected as "binning=0" and 2x2 is "binning=1" in the script.