chemm me

Help!! New question here: From Labview example, there is a compac rio for motor control . I wanted to modify this for my application, which is to do velocity controller. I run my modified program but the motor didn't move. I don't know why. The screen shots attached are not of my modified program as i have forgotten to save my new program in my thumbdrive, thus no screenshot of my new program. Thus hope the old screenshots will help to illustrate what I am asking.. In the host vi screenshot, i print-screen on a computer that is not installed with labview FPGA, so that explains the blurred image of read/write fpga nodes. Q: Can anyone please kindly expain to me the flow of how 'PWM duty cycle (ticks)' is derived by fpga? Is it right to say it starts in the closed loop, with the Discrete PID, where it calculates the 'PWM duty cycle (ticks)'. Then sends to the PWM loop (2nd loop in the pic)? The host vi is not involved in writing pwm duty cycle tick, is this right? Cos i duno if the problem lies in the PWM dyty cycle? So i need to understd how it works. FYI, I am using pci 7831 reconfig.

Hi, Better shielding of wires. It's ok now. Thanks. But another problem happens, it shouldn't be the hardware problem. In the program, the user sets the count limit. But as the counter/lin-encoder jumps and reaches the count limit, the loop is not stopped, though it is supposed to. Is this due to the pwm frequency too fast for the quadrature encoder? Chemm.

Hi thank you all.. I tried common ground for fpga board, encoder circuit and it works abit better. At least the counter didn't jump too crazily. But still, the counter isn't working as correctly like when the motor is manually turned. Still some noise. I have schmitt trigger connected at the encoder. Where could go wrong? Chemm.

Hi, i am using LV8.0, FPGA Module8.0, PCI-7831R. Pls see my attachment under "demo2.vi" & "all functions2.vi" in the project. My focus is on the PWM and quadrature decoder. There is something wrong, when I run the DC motor, the counter showing counts of the DC motor (print head) jumped impossibly quickly. But the counter doesn't jumped according to the movement read by my linear encoder. Is there something wrong with the codes? Pls help me....Thank You.. Chemm.