Reply by Yingtuo June 2, 20092009-06-02
  I m making a simple PID controller with notch filters in Xilinx
blocks. it always prompt the following errors for the blocks in my
notch filter.  if i delete the error block or change the latency to 1,
the same error will happen to another block in the notch.

  Is there a general guideline to determing the latency of each block
or is there any other possible causes of this internal error?

 Thanks a lot

Error 0001:

Reported by:
  'PID/Second-order IIR/AddSub2'

An internal error occurred in the Xilinx Blockset Library.

Please report this error to Xilinx (,
in as much detail as possible. You may also find immediate help
in the Answers Database and other online resources at

Since it is possible that this internal error resulted from an
unhandled usage error in your design, we advise you to carefully
check the usage of the block reporting the internal error. If
errors persist, we recommend that you restart MATLAB.
Error occurred during "Simulation Initialization".