Hi everyone!
i have some issues with my PID (FPGA) controller...
indeed i use it to control the transmitted power of a tunable optical filter. the setpoint is the power i want to transmit and the process variable is the actual power. if the setpoint is greater than the process variable, the pid output increase the voltage and if the setpoint is lower than the process variable, the output decrease the voltage.
but apparently here, the pid doesnt compare the setpoint and the process variable as it should be...
you can find attached a screen shot of my vi's the one on the top is my fpga vi and the one at the bottom is my host vi.
i have been trying to understand the problem all day but i give up !
i hope you will find where my mistake is.
the HP8153 is the power meter which reads the output power of the filters and the subvi N->B converts the value from Analog to Binary and B->N does the opposit.
thanks in advanced !
Yanis
