AAD04A Analog Input Card Refresh Rate

  • I am having an interesting issue where the analog input is updating extremely slowly. I have a laser sensor that outputs 0-10V, this signal wire is landed on V+, the V- has the same ground that the sensor is using and com and v- are connected.

    I can see on the multimeter the sensor output switch from 0 -> 10V instantly but on the card it's updating at about 35/sec (0-600, respective to my 0-10V).

    Anyone have any idea why my refresh rate would be so slow?

    It's on a R30iB controller.

  • AD
  • According to the specs, the input filter delay on that card is 50ms, or 20Hz. Sounds like you are doing a bit better than that.

    If you need speed, you will have to buy an AAD04B2 module. It runs at 500Hz.

    Check out the Fanuc position converter I wrote here!

  • What I mean by 35/sec is I can watch the analog input slowly climb till it maxes out. If I switch the input from 0V to 10V instantly, the input goes from 0-600, but not instantly, it takes about 20seconds. And similarly when switching from 10V to 0V.

    I thought that it takes in whatever voltage it's getting and converts that to an output, and would do this conversion at 20HZ?

  • HawkME, I mean the analog value is changing at 35/sec. When I switch the voltage from 0->10 the analog value after 1 second is around 35, not at 600 like it is after I let it settle for ~20sec.

    Nation, I just checked and they are the same.

  • That sounds a lot like a large capacitance on the line somewhere. I would suggest putting a high-impedance meter directly on the input contacts of the analog card (not at a distance along the input line), and monitor the voltage change there. Or plug a reference test voltage directly into the analog input card with a short, clean pair of wires.

    If the analog card response is still laggard even with the input line eliminated, the card may be suspect.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account
Sign up for a new account in our community. It's easy!
Register a new account
Sign in
Already have an account? Sign in here.
Sign in Now