Cannot Communicate via USB with the FEM Interface Board
- Basics: Make sure that the USB cable is plugged into the
computer and the FEM IB. Make sure the FEM IB is properly powered. At
the very least, the LOCK light (top row, second from right) should be
lit, indicating that the FPGA is powered and has achieved lock.
- If the FEM Interface board has just been powered up, you may
need to hit the recessed RESET button on the FEM Interface board. Upon
power-up, some versions of the FEM IB code require this reset because
the USB lines settle more slowly than the power-on reset which causes a
bad command to land in the FEM IB and lock up the slow control
communication. An indication that this is a problem is if the EMPTY
light on the FEM Interface board (top right LED) is OFF and stays off
when you issue a command. This means that the slow control command FIFO
has received a command and not emptied it from the FIFO because it
looks like a bad command.
- Make sure that the black screen that pops up with the GUI is
not making any complaints about the USB communication. If it is, it is
possible that you have not selected the correct USB device on the
chain. The GUI has a pull-down menu on the lower-right portion of the
screen, next to the GUI selection button, which allows you to select
different devices. Trial and error will tell you which one you happen
to have on your particular setup.
Cannot communicate from FEM IB to FEM module
If you are
communicating between the FEM IB and the FEM, then you should see the
top row of LEDs (3 right-most lights) reflect the command that you have
sent from the gui. If this isn't the case, then communication is
broken.
- Make sure that the FEM is fully seated in the crate. A common
indication that the FEM is not fully seated is that the top row, 3
right-most lights will all be red.
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Cannot achieve slow control fiber optic synch with ROC card:
If
slow control fiber optic synch is achieved with the ROC card then the
top row, left-most LED on the FEM front panel should be lit green. If it
has not been achieved, something is broken in the chain talk from
FEM-->ROC and/or ROC-->FEM.
- Make sure that the ROC card is powered on and the fiber is connected in the correct position.
- Make sure that the BCO clock is being delivered to the
FEM_IB and propagated down to the ROC. The BCO clock comes either from a
GLINK card plugged into the FEM IB or a spartan-3 2-wire cable plugged
into the locations where the BCO would be on the GLINK card. Is the
Spartan-3 card powered on, producing a clock, and is it plugged into the
correct position on the FEM IB?
Cannot achieve data fiber optic synch from ROC-->FEM
If
synchronization is achieved on the data fiber(s) then 8 LED lights per
fiber bundle should light up green in the middle portion of the FEM
front panel.
- Is the appropriate FPGA on the ROC card powered and programmed?
- Has slow control fiber optic synch already been achieved?
This must be achieved before a slow control command can be sent down to
the ROC card to send synch words back up the data fiber.
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