just my two cents on sonics
the sti's we had on g5's and lasers with virtual treadle are programmed for the unit
we had issues with measuring and eventually the manufacturer allowed us the software to reprogram the unit ourselves (not sure I still have the program been 3 years since I was with the company) so that we could play around with values in the field when we had a customer with site conditions that tricked the sonic. causing poor measurement.but a basic idea of the settings
identity.. the sonics are programmed to be a unit # such as 1,2or3 ie. 1 left 2 right 3 top. this allows the board receiving the input to know which sonic it is talking to, then there are pulse settings how many per minute, and ranges in mm as look for a signal between here and there only disregarding approx 16' from floor and lower and disregard 8 inches from face of sonic. that way it doesn't pick up trenches in the floor or grates or undercarriage and think its a vehicle, or pick up other interferenc .there are also settings to allow for temperature change adjustment.
this all had to be done with an rs232 to serial converter. wiring the converter to the blue and orange wire of the sonic and running the program talking through the chosen com port on the laptop running the custom software.
probably useless info but that's what I seem to be full of