PCO.IMAGING pco.1200 hs, Руководство пользователя

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Chapter 4
‚
Data Interfaces
page 31
camera-API, itself, distinguishes between the different in-
terfaces and accesses the IEEE1394 driver-stack. This
stack uses an asynchronous serial data channel for the
command and status information in both directions and
an isochronous channel to transfer the image data from
the camera. The various channels are connected inside
the camera to the dedicated hardware, such as Camera
Operation Code – processor and controller FPGAs.
commands, status image data
Figure 4.2: Firewire 400 example of the command structure layer model
used with the pco.camera systems.
4.2 Firewire 400
Firewire400 (IEEE 1394a) is a serial Bus- system with a
400 Mb/s bandwidth. Up to 63 cameras can be con-
nected on one bus. The maximum (guaranteed) transfer
speed over the isochronous channel is 32 MB/s.
The standard cable length is 1.5-4.5 m. Longer cables,
ranging from 10-20 m are possible within the specification
of IEEE 1394a and are available on request. The
pco.camera system is fully compatible with the Firewire
so hubs to stretch the distance between the camera and
the computer work well (two hubs with 10 m cables result
in a working distance of 30 m). Optical repeaters are rec-
ommended for longer distances. These devices are avail-
able upon request and provide a working distance of sev-
eral hundred meters. The standard connector is the stan-
dard connector used in pco.cameras is a six-pin Firewire
connector.
OEM and system integrator information:
The Firewire hardware (OHCI) has a standardized soft-
ware interface, but it does not include the implementation
of APIs or camera functions like DCAM. Detailed informa-
tion can be found on:
•
http://www.1394ta.org/
•
http://www.apple.com/de/firewire/
•
http://www.1394la.com/
• http://www.linux1394.org/
User Manual pco.camera status 12/2004