bmnhy 19 Tháng một 2007 - #1 Generate an Analog Output (Lượt xem: 1,031) Using Load DAC Does Not Generate an Analog Output on My Motion Board Primary Software: Driver Software>>NI-Motion/FlexMotion Primary Software Version: 6.1.2 Primary Software Fixed Version: N/A Secondary Software: N/A Problem: I have a PCI-7344 motion controller board and would like to use one of the Analog Output channels to send an analog signal to my motion system. I have a servo motor and would like to control the motor programmatically rather than through the built in functionality and PID loop of the board. I have set up a very basic program that reads an encoder on Channel 1 and then attempts to send a signal out of DAC Channel 3. I am seeing a very small voltage occasionally, but otherwise the output remains at 0. Why am I not seeing the correct voltage? Solution: The first thing to make sure is that you are passing the correct number to the DAC Value input. Remember that this input requires a 16-bit number, which means the parameter range is -32,768 to +32,767, corresponding to the full ±10 V output range. Be sure you are not simply inputting a number between -10 and 10. If this is correct, then the second thing to check in your case is how you have Axis 3, which is where the Analog Output 3 falls, configured. In order for the Analog Output to work correctly, you must configure a Stepper motor, OT servo. This can be changed in Measurement & Automation Explorer (MAX) under Axis Configuration. Simply change the axis to stepper or disable the axis completely, the remaining fields do not matter, and be sure to apply and initialize those changes before running your application again. Related Links: National Instruments Motion Control Support Example Program: Generate Analog Output Signal From Motion Board with LabVIEW Example Program: Generate Analog Output Signal From Motion Board with CVI KnowledgeBase 23TGLK8M: How Much Current Do the Analog Out Channels Source for the NI 7344 Motion Board?