52-51413 REV B
9
4 THEORY OF OPERATION
4.1 ELECTRONICS INTERFACE BOARD
The electronics interface board assembly contains the following circuits: Power
Conditioning, circuits required to decode Focus, Zoom, Exposure and other special
commands and RS-485 circuits.
Details of interconnections between the electronics Interface board, the camera module
and the main connector are shown on Wiring Diagram 52-51412.
4.2 VIDEO SIGNAL
The camera module within the camera assembly generates a HD-TVI signal.
5 TROUBLESHOOTING
5.1 GENERAL
In the case of any sort of malfunction of the camera system, it is wise to resist the
temptation to completely tear down the system and start replacing components
indiscriminately. Many times, a quick call to the ROS Technical Support Department will
help with restoring operation with minimum effort. Most failures in the field generally tend to
be cabling problems, and the camera is typically the least likely cause.
If any camera functionality is lost, you may not be getting power to the camera. Turn off the
power and disconnect your cable from the camera. Then, turn on the power and measure
the voltage at the camera end of the cable according to your
camera’s pinout. If there is
no voltage or low voltage, then you have cabling issues. Normally, all voltage levels
present at this connector are referenced to Signal Common (normally Pin 2.) Camera
power should be b11 and +26VDC.
It is a common mistake to reverse RS-485 channels on the controller side. In other words:
Controller RS-485 channel (A) is connected to camera channel (B) and vice-versa, which
can lead the user to think that the camera is not responding to commands. Swapping
communication channels while power is applied to the camera will not cause damage to
any of the RS-485 transceiver electronics.
If all video has been lost, use a standard DVM on the ohm scale to check the center
conductor of the coax for continuity. This is normally Pin 5 on the standard connector, and
exits the user controller on the middle pin of the BNC connector for example. Normal
resistance should only be a few ohms unless the system cable is extremely long. If all
appears well at this point, the next step is to open up the camera housing and check the
electronics Interface board and internal wiring for proper operation.
