Moog Components Group Prizm Fiber Optic USB 1.1 Link Manual
February 17, 2009
Page 7 of 9
1.6.2 OPTICAL SECTION TESTING:
If either Fiber Link light fails to illuminate after power has been applied to both boards and a fiber
optic tether is placed between the Local Host and Remote Hub units, there is a problem with the
optical link and one or more of the following conditions may be present.
•
The fiber is broken or damaged.
•
One of the optical transceiver modules is defective.
•
Excessive light loss (low received optical power) is being experienced.
•
The Prizm Fiber Optic USB 1.1 Link (not the optical transceiver module) is malfunctioning.
•
There is not enough attenuation in the optical link and the receiver is saturating.
To determine if the fiber is broken, a laser module is out, or the board is malfunctioning, first:
•
Check that the optical fiber cable is straight at connectors on board for minimum optic loss.
•
Check the optical level with an optical power meter at each optical connection including any
external WDM’s or sliprings.
•
If the above steps do not yield a solution, one or both boards may be malfunctioning. Try
replacing each board with a spare unit.
1.6.3 DATA SECTION TESTING:
If USB 1.1 data cannot be transmitted and received between the host and peripherals and the optic link
has been verified, there is a problem with one or both Prizm boards. Based on the LEDs present on
both boards, investigate the following:
•
If one or both of the Fiber Link LEDs is not illuminated, refer to Section 1.5.2.
••••
If the USB Link LEDs do not illuminate on both boards as described in Section 1.4.3, verify that a
USB 1.1 compliant Host and at least one USB 1.1 compliant peripheral are attached to their respective
ends of the link. Also verify that both Fiber Link LEDs are illuminated.
••••
If the Host Present LED does not illuminate, verify that a USB 1.1 compliant Host is connected to the
Local Host Board and that both Fiber Link and USB Link LEDs are illuminated.
••••
If a Port 1-4 LED does not illuminate when a valid USB 1.1 compliant peripheral is attached to the
corresponding port, verify that there is a valid USB 1.1 compliant host connected to the Local Host
Board and that both the Fiber Link and USB Link LEDs are illuminated.
••••
If all LEDs behave as expected, but data cannot be carried across the link, examine any device drivers
needed to correctly operate your USB device. Connect the USB peripheral directly to the Host device
and verify proper operation. Then, reinsert the Prism USB Link and assess the status of the system
again.