Camera Operation & Features
21
PixeLINK PL-A780
Document No.: 04646-01
MACHINE VISION CAMERA
SYSTEM GUIDE
Copyright © 2004 PixeLINK
All Rights Reserved
Power
The host computer can supply power to the camera via the FireWire bus if the computer has
a six-pin FireWire connector and the total power demand on the bus does not exceed the bus
capacity.
Other systems—such as laptop computers or those with several FireWire devices daisy-
chained—require an external 12 V supply to power the camera. This external power supply
must be connected to the FireWire bus. For information about laptop accessory kits that
include external power supplies, contact your PixeLINK vendor.
Power Demand
A single PL-A780 draws 5 watts from the FireWire cable or 417 mA @ 12 V.
Power Limitations
The power capacity of the bus depends on the FireWire adapter card installed in the host
computer. To comply with the FireWire specification, the adapter card may supply a
maximum of 1.5 A per FireWire port. However, it is permissible for the card’s limit to be lower
than 1.5 A per port (say, 1.0 A). Note that many cards do not state their current limits.
In a multiple camera system, the current required per camera increases with each
additional camera attached to the bus. Each additional camera causes the bus voltage
to drop, so the current demand is increased to maintain a constant power draw of 5 W
per camera.
Hence, most two-port FireWire adapter cards can be used to power two cameras
simultaneously.
If the current demand exceeds the card capacity, the status lights on the cameras will switch
off. The status light is located above the FireWire connectors as shown in Figure 10 on page
18.
4.6.2 Status LED
The PL-A780 has a Status LED that indicates the hardware and operational status of the
camera. The LED indicates the following behavior:
•
Flashing orange indicates that the camera is initializing.
•
Solid orange indicates that the camera is loading the FFC parameters from
memory. This process takes approximately 20 seconds.
•
Solid green indicates that the camera is ready for operation.
•
Flashing green indicates that the camera is performing a lengthy operation or
is streaming video data.
•
Flashing red indicates that the camera has issued a warning on the latest
command received.
•
Solid red indicates that the camera has experienced an unrecoverable error.
4.6.3 Machine Vision Connector - Trigger and GPOs
The PL-A780 is equipped with a 6-pin Hirose connector for external control of a trigger,
strobe or pulse as shown in Figure 10 on page 18.
