Highland Controls Posted January 24, 2013 Share Posted January 24, 2013 I have an application that I would like to use the Clipper on. The issue might be the PWM DACs. I will be using some of the analog outputs to drive an external data acquisition system. The output data will represent things like position and force(scaled from an analog input). Some of these DACs will be updated at the default servo rate from a PLC. What are these outputs going to look like? Will they be a good representation of a true DAC if I have the PWM freqency high enough? Will they be noisy? Link to comment Share on other sites More sharing options...
steve.milici Posted January 24, 2013 Share Posted January 24, 2013 There is a very good discussion in the Clipper Hardware Reference on what the frequency and amplitude of the generated ripple from the filtered PWM DACs under various PWM frequency settings. Link to comment Share on other sites More sharing options...
Highland Controls Posted January 24, 2013 Author Share Posted January 24, 2013 Thanks. That is a good explanation. My customer's DAQ system has configurable filters, so I should be able to get rid of the ripple. Link to comment Share on other sites More sharing options...
steve.milici Posted January 24, 2013 Share Posted January 24, 2013 You can't completely remove the ripple (as the document states) but you can reduce it to some extent. There is a True DAC option for this controller: ACC-8ES. This board stacks onto the Clipper. Link to comment Share on other sites More sharing options...
Highland Controls Posted January 24, 2013 Author Share Posted January 24, 2013 I need 3 analog outputs, so I think I am stuck with PWM on the Clipper, or will have to go to a UMAC. I have access to a Clipper demo unit, so I think I will try it and see how the output looks. Link to comment Share on other sites More sharing options...
steve.milici Posted January 24, 2013 Share Posted January 24, 2013 Note that the ACC-8ES is field installable. Link to comment Share on other sites More sharing options...
Highland Controls Posted January 24, 2013 Author Share Posted January 24, 2013 That should work. I will get Opt. 12 for the analog input channel, then Acc 8ES for the true DAC outputs. Link to comment Share on other sites More sharing options...
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