A few years ago while working in the large storage lap at HP, I was faced with
a problem of locating the opposite end of many long Fibre Channel cables. My
first design offered a set of high intensity LEDs that flashed in an alternating and repeating pattern on both the transmit
and receive sides of the FC connector.
The second design, as seen in the photo, has both an improved version of the
flashing LEDs and uses an intelligent LC GBIC that is used to calculate signal loss in a cable under test. I used a Z8 microcontroller to communicate with the GBIG for diagnostic information, drive a 16x2 LCD,
act on the 4 operator push buttons, and manage power usage. The biggest challenge
in this project was the development of the I2C serial interface used to communicate with the intelligent GBIC. I have developed the design, including
a custom designed PCB using surface mount components as if it was to be built in limited volumes for retail sales.
The tester currently has 2 primary functions, selected by pressing the appropriate
button. The first function is the flashing blue LEDs, user selectable to flash
the LEDs on the transmit side, receive side, or both transmit and receive. The LEDs are mounted within a LC connector header.
The use is straight forward, set the FIND operating mode, connect one end of the FC cable to the tester, then go look
into the questionable FC cables, looking for flashing blue light.
The second mode of operation the diagnostic GBIC to test for signal loss
through a FC cable path. If you have a FC cable that you suspect may be defective,
connect the cable to the Tester GBIG and connect a loop back connector to the other end.
The tester will report in real time the percentage of returned laser light.
Of course there are a number of other functions, such as calibrate, information,
and test time that the user can access.
If you have interest in one of these testers, contact me…
