Decatur Electronics SI-3 - Target Select; Cosine Horizontal and Cosine Vertical; Update Rate; Hold Time and Speed Lock

SI-3
™
User’s Manual
13
"Approach“ will show vehicle speeds coming towards SI-3™, and
"Recede" will show vehicle speeds going away from the SI-3™.
4.8 Target Select
A Target Select value of “Strong” is the standard SI-3™ conguration.
Changing to “Fast” will report the fastest vehicle seen within the
range of the SI-3™.
4.9 Cosine Horizontal and Cosine Vertical
For bridge-type installations where the SI-3™ is over the trac and
pointing slightly down, the vertical angle can be entered here to
ensure that the SI-3™ calculates the correct vehicle speeds. For
installations where the SI-3™ is at a signicant angle from the road,
the horizontal angle can also be congured. These two may be used
together. Keep the angles between 0 and 45 degrees for maximum
accuracy.
4.10 Update Rate
The selected message format will be sent in whatever time interval
(in milliseconds) that you set. The "Update Rate" can be as low as 20
milliseconds. The number should be a multiple of 20 milliseconds.
The "Update Rate" and the amount of serial port activity do not aect
the measurement accuracy of the SI-3™.
4.11 Hold Time and Speed Lock
When the "Speed Lock" is congured as "Use Hold Time", the "Hold
Time" value indicates the time the vehicle speed is displayed after
the vehicle moves out of range. If the "Continuous Update" is selected
this value has no aect.
4.12 Sensitivity
The SI-3™ is shipped with a default "Sensitivity" of 9, this should work
for most applications. The sensitivity can be increased for longer
range or decreased for closer range. If the sensitivity is too low the
SI-3™ may take too long to lock onto and display a speed.