Operating instructions

change and when changing to or from Daylight Savings Time. The response is "Time
Off: 05:30:00" followed by the command prompt.
trigger
This causes trigger to be enabled. The response is the command prompt. (However, if
the command is issued during the "Off" duration, the response is "Turn Off: <time>,
where <time> is the current time, followed by the command prompt.)
Once trigger is enabled and the PC clock is within the "On" duration (from turn-on to
turn-off), the Video Sentinel box looks for above-threshold changes in the video image.
If it sees enough of a change, an event is generated and up to 6 seconds of video are
captured in the Video Sentinel box. The PC then transfers a subset of the video data
(centered on where the change occurred) from the Video Sentinel box to a file in the
current directory. This file can be viewed with the sdisplay program described below.
stop
This causes trigger to be disabled. The response is the command prompt.
(Unfortunately, there is a bug in the code that sometimes prevents the command prompt
from reappearing. Then, the only recourse is to force the application to quit by pressing
control c.)
test
This runs a test of the Sentinel Box memory. 200 frames of pseudo-random data are
written to the Sentinel Box memory. Then, these frames are read from the Sentinel Box
and verified. If an error is detected, the expected value and the actual value are
displayed. At the end of the test, the total error count is reported.
maskcapture testmask.dat
This writes the current mask within the Sentinel Box to the file: testmask.dat
This command can be used to verify that the mask (which was set with the "mask"
command) has not been corrupted.
perhour 20
This command sets the event rate limit to the specified value (in this case 20). The
default is 12 events per hour. Whenever the number of events in the last hour exceeds the
event rate limit, the sentuser program will go to sleep after each subsequent event long
enough to strictly limit the event rate to the specified value. This helps to keep us from
filling up the disk with erroneous events during lightning or wind storms.