VB3i MANUAL
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22 May 2014
Analogue and digital outputs (AD1 & AD2)
The AD1 and AD2 connectors each have 1 analogue voltage and 1 digital output. The digital output on connector AD2
is a frequency/pulse output corresponding to velocity. The pulse per meter range is adjustable in software. The digital
output on connector AD1 is a simple on/off state output. This digital output can be associated with any of the data
channels being logged by the VBOX. A threshold level can be set for the selected data channel where a true condition
gives a 5v output and a false condition gives a 0v.
I.e. Data channel –Speed, threshold 40Km/h. When speed is >40 output = 5V, speed, 40 output = 0V
A hysteresis and tolerance value can also be associated to this condition.
The default function of this digital output is to indicate the current logging status of the VBOX.
The analogue outputs on connectors AD1 and AD2 are both user configurable. For example, analogue output 1 could
be configured to output velocity while analogue output 2 might be configured to output lateral acceleration. The
voltage range of both analogue outputs is 0 to 5v DC.
Digital inputs (D IN)
The ‘D
IN’ connector contains the two digital inputs for the VBOX3i. Digital input 1 is also referred to as the brake
trigger input. This input is connected to an event capture input on the GPS engine. This captures precisely the trigger
event time (10nS resolution) for use in brake distance calculation. This period of time is called the trigger event time,
and is logged and used to correct the measured brake stop distance to the exact point at which the trigger was
pressed.
A hand-held brake trigger is also available to allow the user to record marker events in the VBOX3i data file.
A remote logging on/off switch is also available for ease of use and when the front panel switch is not accessible.
