Technical Application Note TAN2009001

Technical Application Note TAN2009001
Creating a board-level multiple camera array for OEM applications
Revised February 5, 2009
1.1.
Subject
Technical Application Note (TAN2009001): Creating a board-level multiple camera array for OEM
applications
1.2.


1.3.
Applicable Product(s)
Firefly MV (OEM models)
6-Port Board Level 1394a Hub
Application Note Description
This Technical Application Note describes some of the factors to consider and the specifics of how to
construct a flexible, ultra-compact, multiple camera digital imaging system using an array of eight
Firefly MV IEEE 1394a cameras, a custom Point Grey 6-port board-level 1394a hub, and third-party
custom cables.
1.4.
Intended Audience
This Technical Application Note is intended for original equipment manufacturers (OEM’s) of high
volume vision systems. Some of the Point Grey products described within, such as the Firefly MV
camera with miniature 1394 connector and the 6-port board-level hub, are available to qualified OEM’s
only. Some minimum order quantity (MOQ) and lead time restrictions may also apply. Contact Point
Grey Technical Sales for additional information.
1.5.
Overview
Many high-speed, compact vision systems, such as 3D scanners, object and gesture tracking
systems, and multi-touch displays, have the following imaging requirements:
 Multiple cameras must acquire and stream images simultaneously from different viewpoints;
 Synchronized image acquisition from multiple cameras, either automatically in free-running
mode, or by using an external trigger; and
 The cameras and supporting components must fit in a tight space, be placed in a unique
position, or mounted within a custom enclosure.
This document will provide the following information:
 An overview of some of the benefits of FireWire and why it is an ideal interface technology for
small, multiple camera systems;
 How Point Grey products can be used to meet some of the above requirements;
PGR, the Point Grey Research, Inc. logo, Digiclops, Dragonfly, Dragonfly Express, Chameleon, Firefly, Flea, Ladybug, Scorpion and Triclops are trademarks or
registered trademarks of Point Grey Research, Inc. in Canada and other countries.
Copyright © 2008 Point Grey Research, Inc. All rights reserved.
Point Grey Research TAN2009001
Creating a board-level multiple camera array for OEM applications
 Some of the technical factors that vision system designers should be aware of when designing
with Point Grey products; and
 An example system configuration.
Figure 1: Demonstration of a board-level multiple camera array
1.6.
Multiple Camera Support
1.6.1.
Selecting a Digital Interface
There are several things to consider when deciding on the interface technology for a multi-camera
system, including total throughput, quality of service, latency, and overall system complexity and cost.
FireWire is widely regarded as the best interface technology for industrial and computer vision
applications. It has guaranteed, truly isochronous bandwidth that is allocated every 125 µs for data
that can be termed "latency-critical." This allows for low-latency data distribution and enables the
latency of that data to be deterministic, making the interface technology ideal for operating multiple
cameras on the same network. FireWire also allows for much smaller camera designs, like those of
many analog cameras, and a single cable can provide both power and data. This maximizes ease-ofuse and reliability of the system, and enables compact multiple camera imaging systems to be created
with minimal cabling.
The Point Grey Firefly MV uses an IEEE 1394a interface, which provides data throughput of 400
Mbits/s.
Additional resources:
 Article: FireWire: Blazing the Way for Industrial Vision
 Presentation: Past, Present and Future of FireWire and USB Technology
1.6.2.
Multiple FireWire-Based Camera Arrays
There are many factors that should be taken into account when designing a large array of FireWire
cameras. These include physical elements such as hubs, cables and host PCs, as well as other
aspects such as image acquisition software.
Technical Application Note 2008001 provides an detailed examination of the various factors to take
into consideration when designing and implementing a multiple camera array.
Revised 5-Feb-09
Copyright © 2009 Point Grey Research, Inc. All rights reserved.
2
Point Grey Research TAN2009001
Creating a board-level multiple camera array for OEM applications
Additional resources:
 TAN2008001: Factors to Consider When Designing a Multiple Camera Array
1.7.
Image Acquisition Synchronization
All Point Grey 1394a and 1394b cameras, including the Firefly MV, support image acquisition
synchronization. When in free running mode, the cameras are automatically synced to within 125μs at
the hardware level. This is a feature of the cameras themselves, and is independent of the host
system, camera drivers or software. Synchronization can also be achieved by triggering all cameras
at the same time, either by an external trigger or by an asynchronous software trigger.
Point Grey’s MultiSync software can also be used to perform automatic synchronization of cameras
across buses. The software is also capable of synchronizing cameras across multiple PCs using a
dedicated IEEE1394 timing bus.
Additional resources:
 Knowledge Base Article 241: Synchronizing image acquisition of multiple PGR cameras
1.8.
Board-Level Products
The term “board-level” refers to a product that does not have a case or protective enclosure that
houses the printed circuit board (PCB). This is often necessary to minimize space requirements or to
allow the camera to be mounted within a custom enclosure. Board-level versions of the Firefly MV,
Dragonfly2, and Dragonfly Express are available for OEM applications.

Electrostatic discharge (ESD) precautions should be taken when
working with or handling board-level products. Users who have
purchased a bare board camera should either handle it bare handed or
use non-chargeable gloves, clothes or material. Users should also use
conductive shoes, and should install a conductive mat on the floor or
working table to prevent the generation of static electricity.

Some Point Grey board-level products are not FCC or CE certified.
Emissions compliance certification of these products are the
responsibility of the system manufacturer.
Revised 5-Feb-09
Copyright © 2009 Point Grey Research, Inc. All rights reserved.
3
Point Grey Research TAN2009001
1.9.
Creating a board-level multiple camera array for OEM applications
Example System
Point Grey Research has successfully demonstrated an array of eight Firefly MV IEEE 1394a
cameras, a custom Point Grey 6-port board-level 1394a hub, and third-party custom cables. Point
Grey Research does not endorse any of the third-party products mentioned or account for their
performance in your particular setup.
Figure 2: System diagram for board-level multiple camera array
1
Component
Product
Computer
Sony VAIO All-in-One PC, model VGCLT33CE
Operating System
Windows XP Service Pack 1
Cameras
Point Grey OEM board-level Firefly MV camera with mini connector
Part numbers 1 : 97-00100-06900 (mono), 97-00100-07300 (color)
Some ordering restrictions and minimum order quantities apply
Revised 5-Feb-09
Copyright © 2009 Point Grey Research, Inc. All rights reserved.
4
Point Grey Research TAN2009001
Creating a board-level multiple camera array for OEM applications
Camera Operation Settings
Image format: Format_7 Mode1 (2 x 2 pixel binning), Mono8 pixel
encoding
Resolution: 320 x 240
Packet size: 320 bytes per packet
Frame rate: 30 frames per second
Hubs
Point Grey OEM board-level 6-port hub with mini connectors
Part number1: 97-00400-00000
Interface Card
Point Grey 1394b 800 Mb/s 2-port ExpressCard (FWB-EC-2PORT)
Supported bandwidth: Single lane (x1) PCIe serial link
Interface Card Power Supply
Point Grey 12 V 1.25 A wall mount power supply (ACC-01-9003)
Software and Drivers
Point Grey FlyCapture SDK with FirePRO interface card driver
Cables (Card to Hubs)
Point Grey 6-pin to 9-pin 4.5 m 1394 cables
Cables (Hubs to Cameras)
8-inch custom cables, 8-pin JST to 8-pin JST
Newnex part number: CFS-JST8-08A
Optics
6 mm M12 microlens
1.9.1.
Imaging Components
1.9.1.1.
Firefly MV with Miniature 1394a Connector
The Firefly MV can be fitted with a miniature 8-pin vertical connector in place of the standard 6-pin
right-angle (vertical) 1394a connector. This model, available to qualified OEM’s only, is designed to
minimize the amount of space required at the rear of the Firefly MV. The following Technical
Application Note TAN2006007 - Wiring specification for Firefly MV mini 1394 connector documents the
part number and pin configuration of the connector used on this model. This allows users to create
their own custom IEEE 1394 cable for connecting to the miniature 1394 connector.
Camera Specifications:
 IEEE 1394a 400 Mb/s interface
 1/3” Micron CMOS with global shutter
 0.3 MP at 60 FPS
 Ultra-compact 25 x 40 mm size
 C/CS lens mount
Figure 3: Firefly MV PCB dimensions
Revised 5-Feb-09
Copyright © 2009 Point Grey Research, Inc. All rights reserved.
5
Point Grey Research TAN2009001
1.9.1.2.
Creating a board-level multiple camera array for OEM applications
6-Port Hub with Miniature 1394a Connectors
Hubs can help to extend the distance of Point Grey cameras, reduce the number of cables arriving at
the host PC by consolidating connections, and provide additional power over the FireWire cable to
connected cameras. The 6-port hub supports up to 5 incoming connections which then can be
reduced to a single cable to the interface card on the PC (note that the total amount of data that can
be transferred is still limited by the 1394 bus). Two hubs can also be daisy-chained together to support
an 8-camera array off one 1394a host adapter card (requires external power to be applied).
Hub Specifications:
 65 x 40mm (see full dimensions below)
 One (1) flat 6-pin IEEE-1394a connector; five (5)
vertical 8-pin miniature 1394a connector JST p/n
BM08B-SRSS-TB(LF)(SN)
 8 - 32 V via external barrel connector or FireWire
 1 A per port at 12 V
 TI TSB41LV06A physical layer chip
 Status LED to indicate power and device connection
 Common mode chokes minimize physical layer port
errors and failures
 4 mounting holes
Figure 4: 6-port hub dimensions
Revised 5-Feb-09
Copyright © 2009 Point Grey Research, Inc. All rights reserved.
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Point Grey Research TAN2009001
1.9.1.3.
Creating a board-level multiple camera array for OEM applications
IEEE 1394b ExpressCard
The Firefly MV 1394a camera is fully compatible with the 1394b ExpressCard. The only issues that
users should be aware of are:
 Each camera consumes approximately 1 W of power. An external power supply must be
connected to the ExpressCard to provide power to the cameras.
 The physical interface between 1394a and 1394b is significantly different. To connect the
ExpressCard to the 6-port hub’s 6-pin 1394a connector requires a cable with a 1394a 6-pin
connector on one end and a 1394b 9-pin connector on the other. These cables can be purchased
from Point Grey.
 Using a 1394b interface card will not improve the camera's ability to transmit data. In other words,
users will not be able to achieve higher resolutions and faster frame rates with their 1394a
camera.
 The number of cameras that can be used to stream images continuously is limited by the IEEE
1394 chipset used. The LSI (Agere) chipset used in the Point Grey ExpressCard is able to support
8 simultaneous DMA contexts. This means that 8 cameras are able to stream at any given time.
1.9.1.4.
Custom Cables
Point Grey does not provide the cables required to connect the 6-port hub to the Firefly MV. These are
left to the OEM to source themselves. Newnex is one company that provides these cables. A wiring
diagram is shown in the figure below.
Figure 5: Wiring diagram for cable connecting 6-port hub to Firefly MV
Revised 5-Feb-09
Copyright © 2009 Point Grey Research, Inc. All rights reserved.
7
Point Grey Research TAN2009001
1.9.2.
Creating a board-level multiple camera array for OEM applications
References and Resources
Technical Application Notes:
 TAN2008001: Factors to Consider When Designing a Multiple Camera Array
 TAN2006007: Wiring specification for Firefly MV mini 1394 connector
Knowledge Base Articles:
 Knowledge Base Article 252: Technical overview of the IEEE 1394 (FireWire) standard
 Knowledge Base Article 241: Synchronizing image acquisition of multiple PGR cameras
Datasheets:
 Firefly MV datasheet
 1394b ExpressCard datasheet
Other Websites and Documents:
 Newnex 1394 custom cables
 Past, Present and Future of FireWire and USB Technology
Revised 5-Feb-09
Copyright © 2009 Point Grey Research, Inc. All rights reserved.
8
Point Grey Research TAN2009001
1.10.
Creating a board-level multiple camera array for OEM applications
Additional Downloads and Support
Access more Technical Application Notes on the web at www.ptgrey.com/support/downloads.
Point Grey Research Inc. endeavors to provide the highest level of technical support possible to
our customers. Most support resources can be accessed through the Product Support section of
our website: www.ptgrey.com/support.
Creating a Customer Login Account
The first step in accessing our technical support resources is to obtain a Customer Login
Account. This requires a valid name, e-mail address, and camera serial number. To apply for a
Customer Login Account go to www.ptgrey.com/support/downloads/.
Knowledge Base
Our on-line knowledge base at www.ptgrey.com/support/kb/ contains answers to some of the
most common support questions. It is constantly updated, expanded, and refined to ensure that
our customers have access to the latest information.
Product Downloads
Customers with a Customer Login Account can access the latest software and firmware for their
cameras from our downloads site at www.ptgrey.com/support/downloads. We encourage our
customers to keep their software and firmware up-to-date by downloading and installing the latest
versions.
Contacting Technical Support
Before contacting Technical Support, have you:
1. Read the product documentation and user manual?
2. Searched the Knowledge Base?
3. Downloaded and installed the latest version of software and/or firmware?
If you have done all the above and still can’t find an answer to your question, contact our
Technical Support team at www.ptgrey.com/support/contact/.
Revised 5-Feb-09
Copyright © 2009 Point Grey Research, Inc. All rights reserved.
9
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