SUMMARY:
This article explains the factors to consider when powering a Point Grey camera and defines some common power terminology.
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All Imaging Products •
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ANSWER:
Determining camera power requirements
The power requirements for all Point Grey cameras are listed in the following places:
- The Technical Data Sheet that accompanies each product description on the Point Grey product site.
- The Getting Started Manual and Technical Reference Manual that are provided with the camera. (Note that not all cameras include a Technical Reference Manual.)
In the Specifications table, look for "Voltage Requirements" and/or "Power Requirements/Consumption (max)". Volts are expressed as a range within which the camera is designed to tolerate. For example, the Grasshopper camera can tolerate between 8 - 30 volts. For more information about power requirements, consult the Technical Reference Manual (if included), under Camera Power.
External power source compatibility
Power consumption can be calculated by multiplying volts by amperes (current). For example, a 12-volt 1-ampere power supply provides 12 watts for consumption.
Power can be provided to Point Grey FireWire cameras directly by the host adapter card via the FireWire cable, or through the GPIO port. FireWire cards typically do not provide sufficient power by themselves, so we recommend that you connect the power supply of the host system to the 4-pin connector available on most FireWire cards.
Note: Flea3 FireWire cameras should not be connected to an external power source such as a GPIO. Doing so may cause damage to either the camera, the host, or the external power supply.
Power can be provided to Point Grey USB cameras directly through the USB port via the USB cable, or through the GPIO port. We recommend connecting the camera to a USB port on the back of the computer, which receives power directly from the power supply of the computer. USB ports in the front of most computers are powered through an internal hub, which may not output sufficient power to the camera. Likewise, a camera connected to an external hub may also provide insufficient power. Power and bandwidth information about USB host controllers and hubs can be found in the Windows Device Manager, under 'Universal Serial Bus controllers.'
For GigE and Camera Link cameras, power must be provided by the GPIO interface.
For Zebra2 cameras, power can be provided over the Ethernet interface (PoE) or via the 4-pin Phoenix terminal block on the back of the case (Phoenix part no. 1963447). Two power input pins are provided for daisy chaining multiple cameras to a single power supply or other device. To use PoE, you must also have a powered GigE card, a powered Ethernet switch, or an Ethernet power injector.
If you connect the camera to a hub, internal or external, we recommend supplementing power to the hub with an external power supply. When cameras or hubs are connected to more than one power source, the device uses the power source with the higher voltage.
Point Grey sells a 12 V wall-mount power supply equipped with a HR25 8-pin GPIO wiring harness for connecting to the camera (Part No. ACC-01-9006). For more information, see the miscellaneous product accessories page.
Low- or high-voltage power source issues
In general, the input pins of Point Grey cameras are protected from both over- and under-voltage. However, operating the camera outside the recommended voltage specifications may cause the camera to under-perform. For example, low voltage may cause bus resets, resulting in lost connections with the camera. For more information, including the recommended voltage for driving inputs from a digital logic signal, consult your camera's Technical Reference Manual, under GPIO Electrical Characteristics.
Other power considerations
If you are designing a multiple camera array, the host adapter card may be unable to power all cameras connected to a bus. Point Grey 3-port and 5-port hubs are available, which can output 1 ampere per port at 12 volts, using an external power supply connected to the hub. For more information, see Factors to Consider When Designing a Multiple Camera Array.
Some Point Grey cameras allow the user to power-up or power-down components of the camera using the DCAM CAMERA_POWER register 0x610. The exact components vary between camera models. For more information, consult the Technical Reference Manual for the camera, and the Point Grey IEEE-1394 Digital Camera Register Reference (available with the camera documentation and on the Point Grey download site).
When the power of a camera is disengaged then re-engaged (power-cycled), the camera reverts to its default factory settings, or if applicable, the last saved memory channel. Your camera may have an on-board sensor that allows you to monitor a variety of different voltages. For more information, consult your camera's Technical Reference Manual, under Voltage Sensor.
ARTICLE INFO:
Article ID: |
295 |
Published: |
7/11/2008 9:54:02 AM |
Last Modified: |
6/8/2012 2:07:17 PM |
Keywords: |
power, voltage, volts, amps, amperes |
Issue Type: |
Normal Use |
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