6.5.6 I/O Wiring
The Photonfocus cameras include electrically isolated inputs and outputs. Take great care when
wiring trigger and strobe signals to the camera, specially over big distances (a few meters) and
in noisy environments. Improper wiring can introduce ground loops which lead to malfunction
of triggers and strobes.
There are two roads to avoid ground loops:
•
Separating I/O ground and power supply (ISO_GND and ISO_PWR) from camera power
(CAM_GND, CAM_PWR)
•
Using a common power supply for camera and I/O signals with star-wiring
Separate Grounds
To separate the signal and ground connections of the camera (CAM_GND, CAM_PWR, data
connections) from the I/O connections (ISO_GND, ISO_PWR, ISO_IN, ISO_OUT) is one way to
avoid ground loops. Fig. 6.13 shows a schematic of this setup. In this setup the power supplies
for the camera and for ISO power must be separate devices.
I S O _ G N D
Figure 6.13: I/O wiring using separate ground
.
6.5 Trigger and Strobe Signals for GigE Cameras
S e p a r a t e g r o u n d
1 s o l a t o r
I S O _ I N
I S O _ G N D
G r o u n d p l a n e v o l t a g e d i f f e r e n c e
n o g r o u n d l o o p
C A M _ G N D
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