Setting Up The Rotary Counter - Matrox GatorEye Series Installation And Technical Reference

38 Chapter 3: Matrox GatorEye User Guide

Setting up the rotary counter

To use the quadrature decoder, you must first identify which two auxiliary input
lines are carrying the two-bit Gray code; that is, you must identify which input
line is carrying bit A and which is carrying bit B. To do so, use the
EncoderBitSelector feature to select the bit you are configuring (EncoderBitA or
EncoderBitB) and then use the EncoderBitSource feature to specify the input line
that should carry the bit.
You can set the rotary counter to zero using the EncoderReset feature. Note that
to reset the rotary counter automatically upon an event, use the
EncoderResetSource and EncoderResetActivation features. Set the
EncoderResetSource feature to the source of the event (for example, TimernEnd).
If the source is a line (for example, Line0), use the EncoderResetActivation feature
to specify when, during the transmission of the signal over the line, to cause the
event (such as, the rising edge or falling edge).
You can inquire about the value of the rotary counter at any time using the
EncoderValue feature.
To get the value of the rotary counter when a specific event or signal occurs (such
as, the reception of a signal over a specific line), set the EncoderLatchSource
feature to the name of the line (such as, Line0) or event (such as, AcquisitionEnd)
to trigger the report from the counter. When the specified event or signal occurs,
the rotary counter's value is copied to the EncoderLatchValue feature.