Hi all,
I am working on real time motion control of a dc motor. I have a main
computer and a real time desktop target which has a fpga card.
I use the fpga to do the encoder quadrature decoding and also for
sending the analog signal to the motor drives. My real time desktop
target gets the motor position and generates pid control action. Then,
the control signal is send to the amplifiers using the fpga card. The
problem is as follows:
The vi running in the fpga is in a timed loop of 40kHz. The pid
controller vi runs at the desktop at 1 kHz. I use a timed loop and see
that the loop completed in that desired frequency. However, when I just
try to log the data, it is very slow, it just does not show the changes
in the input and output at every milisecond. For instance, when the
graph does not show all the points either. On the other hand, the loop
does not finish late at all. It just works fine. I could not find out
the problem. Since I read only one point from the fpga at every
milisecond, I did not use any of the FIFO block at all. I did not need
any buffering... What could be the problem be? How can I just read the
input\oupput at every milisecond?totally annoying. Even, if I press
stop control butten for the timed loop, it just takes a while to stop
the control loop as well. I would be happy if you could give a response.
thank you.
