06-13-2006 08:43 AM
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06-14-2006 07:37 AM
06-14-2006 07:45 AM
06-14-2006 08:12 AM
Lynn,
I understand what you mean by the signal threshold and Boolean operation but I am not familiar with the "standard quadrature logic". Could you please explain or give an example. Thanks.
Matthew
06-14-2006 08:28 AM
06-14-2006 08:38 AM
Search for "quadrature encoder" on ni.com. Here is an extract from this link.
Quadrature Encoders
The most common type of incremental encoder uses two output channels (A and B) to sense position. Using two code tracks with sectors positioned 90° out of phase, the two output channels of the quadrature encoder indicate both position and direction of rotation. If A leads B, for example, the disk is rotating in a clockwise direction. If B leads A, then the disk is rotating in a counter-clockwise direction. Therefore, by monitoring both the number of pulses and the relative phase of signals A and B, you can track both the position and direction of rotation.
In addition, some quadrature detectors include a third output channel, called a zero or reference signal, which supplies a single pulse per revolution. This single pulse can be used for precise determination of a reference position.
06-14-2006 09:21 PM