Matrox Solios eA, Установка и справочник по оборудованию, Страница: 69 / 196

Matrox Solios eCL/XCL acquisition section 69
Synchronization
For each PSG, the board can supply one horizontal (HSYNC) and one vertical
(VSYNC) synchronization signal to the video source. Through the Camera Link
connectors, the board also receives synchronization data (frame valid, line valid,
and data valid) along with the video data; refer to the Camera Link specification
for a description of the synchronization data.
Note that the Camera Link standard does not regulate how to transmit an
interlaced video signal; however, you can define an auxiliary signal as a field
polarity input signal and transmit the field polarity on this signal.
Clock
For each PSG, the board can supply a clock signal to the video sources. Through
each of the video input Camera Link connectors, the board can also receive a clock
signal.
Quadrature decoder
The PSGs of all Matrox Solios eCL/XCL boards
1
feature a quadrature decoder
that can decode input from a rotary encoder with quadrature output. This type
of encoder (a quadrature encoder) is a device that provides information about the
absolute position and direction of a rotating shaft. The encoder outputs a two-bit
code (also known as gray code) on two pairs of LVDS wires in a precise sequence,
as shown in the table below.
From this sequence, the position of the rotating shaft and the direction of rotation
can be determined.
The quadrature decoder can decode gray code and update a 32-bit internal
counter. You can read the counter at different stages of the grab or trigger a grab
based on the value of the counter. The quadrature decoder supports a maximum
encoder frequency equal to the pixel clock frequency of the video source.
1. For the standard Camera Link speed Matrox Solios XCL dual-Base/single-Medium
boards (66 MHz), starting from version 100.
Channel Quadrant A Quadrant B Quadrant C Quadrant D
Quadrature channel A 0 0 1 1
Quadrature channel B 0 1 1 0