Command 401

Command 401 controls analog output on channel 4. It's a kinda strange command and rather tersely documented, but has the capacity to be very very useful. Here is some info that's not really clear from the LabPro Technical Reference Manual, or else is in there but I didn't notice it at first (my fault):

• The amplitude parameter seems to control peak-to-trough voltage on a scale where 0 is 0 volts and 4095 is 9.8 volts. In other words, peak-to-trough voltage = .0028 × amplitude
• The offset parameter seems to shift the waveform down by a number of volts where shift = .0012 × offset.
• The -3 V < V_out < 3 V limit mentioned in the manual doesn't seem to be an actual limit either in software or hardware. My LabPro happily put out 3.45 V, but that was when I was trying to push it to output 4 V. When outputting a sine wave, the limit is even higher.
• Turning off analog out with s{401,0,0,0,0} didn't work for me; it would get "stuck" outputting some voltage. The only thing that seemed to work was a reset command or s{401,1,0,0,0}. The latter still left a bit of noise on the line though. EDIT: Logger Pro uses s{401,0,0,0,5}. Maybe that's the key.
• The last example listed for the sine wave output, s{401,6,2,768,10}, should state that it has a peak-to-trough voltage of 2 V, not 1 V.
• The signal generator gets turned off when sampling is aborted with Command 6.