Driving Loads with the PCI/PXI-6704 Gives Inconsistent Results Hardware: Signal Sources (AWG/FG/AO)>>Analog Output Devices>>PCI-6704, Signal Sources (AWG/FG/AO)>>Analog Output Devices>>PXI-6704
Problem: I am doing current output to drive a load with the PCI/PXI-6704, I am expecting to see 5 volts across the load. When I measure the resulting voltage, it seems to rail and/or fluctuate between 0 and 10 volts. What is going on? Solution: Before driving the full amount of current you desire, first drive 0.1 mA of current followed by a 50 ms wait, this should solve the problem. Please see the attached VI for an example of this. This behavior is caused by larger impedance loads that can prevent the output circuitry from settling when enabling the channel. It has been found to occur when driving loads in the range of approximately 6.5 kOhms to 16 kOhms. In this range, the voltage output may fluctuate between 0 and 10 volts if the expected voltage is actually 5 volts. Note: This irregularity is primarily seen if you stop and restart a DAQmx Task repeatedly. Related Links: Attachments:
Report Date: 04/20/2007 Last Updated: 04/21/2007 Document ID: 48JESQ4G |
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
