Camera Link PCI Express (PCIe) Gen1 Framegrabbers
Units, Connectors, and Channels
EDT, Inc.
2012 March 16
8
Units, Connectors, and Channels
This section covers how to work with multiple units, connectors, and channels, which are defined as follows:
unit
EDT product (board)
connector
physical connector (for example, a fiberoptic or MDR26 connector)
channel
DMA channel or, sometimes, simulation channel
Typically, an EDT Camera Link (C-Link) board has two MDR26 connectors and one simulation channel,
while an EDT fiberoptic (FOX) board has one to four fiberoptic connectors with no simulation channel.
In base mode, each camera requires one connector on the EDT board, and each connector provides one
DMA channel. Thus, in base mode, an EDT framegrabber with two connectors has two DMA channels.
In medium or full mode, each camera requires two connectors on the EDT board. In this case, the two
connectors work together to support one DMA channel.
NOTE
In EDT hardware, the connectors are labeled 0 and 1 on some boards, but 1 and 2 on others.
Regardless of the labels on the hardware, the software always counts the connectors in order as 0
(primary), 1 (secondary), and so on, with 0 being the connector closest to the PCIe bus.
If you install one board in your host system, the system will assign the default unit number (0) to that board.
If you install multiple boards, the system will assign a unique unit number to each board, starting with 0 (the
sequence is system-dependent). Typically, the unit number is an argument when invoking an application
(such as
take
or
pdvshow
) or a parameter passed into one of the EDT subroutines.
shows an example of how the software numbers the units (boards) and connectors. The default for
the first unit number, connector number, and DMA channel number is always 0, with additional units,
connectors, and DMA channels numbered as 1, 2, and so on.
Figure 2. Example of Unit Numbering and Connector Numbering
If your EDT board is connected to multiple cameras, the software provides a unique handle to represent
each camera. Unless you specify a different unit number, DMA channel number, or both, any application
(either your own or EDT’s) seeking access to the cameras will default to unit 0, connector 0.
Unit 0,
Connector 0
(primary)
Unit 0,
Connector 1
(secondary)
Unit 1,
Connector 0
(primary)
Unit 1,
Connector 1
(secondary)
Unit ordering is system-dependent, starting with unit 0.
Connector ordering always starts with the connector nearest
the PCIe bus, which EDT software always calls connector 0.