Hi all.
I'm working with an application that is counting pulses from a renco hollow shaft encoder to measure the distance traveled on a single axis platform actuated by a ballscrew and controlled by a stepper motor. The encoder is mounted to the opposite end of the motor directly to the ballscrew.
This said encoder has 100 pulses per revolution and at the moment im using only 1 channel on its output to do the counting. I'm using the single counter channel on a DAQ 6008 to do the actual counting.
Here's my problem.
When i run the motor at a moderate speed and measure the pulse count from one full travel on the axis I get 8200 pulses. If i reverse the motor now and bring it back at the same speed, the return full travel will give the same 8200 pulses which is exactly what I want. However, if i run the motor at extremely slow speeds the same 8200 pulses will equate to only 3 quarters of the travel on the same axis.
My assumption is that at the higher speeds the DAQ 6008 is missing a large number of counts. Am I correct in this assumption?. I will soon have access to a DAQ 6211. Will this provide a more reliable counting device??.
Thanks in advance guys. I would really appreciate some input.