analog trigger with USB-6259

[hellolv]

Hi,

I am writing an oscilloscope VI.  I couldn't get the analog trigger to work like a real scope.  Can someone shed some light on the triggering of USB-6259?

I am trying to trigger off the analog input itself(rising edge).


hellolv

[ryan_d]

Hi hellolv,

The USB-6259 supports three analog triggering modes: analog edge triggering, analog edge triggering with hysteresis, and analog window triggering. You can perform analog triggering off of any one of the analog input channels, APFI0, or APFI1. This information is located on page 3 of the NI 625x Specifications.

Additionally, the NI Developer Zone tutorial: Tips and Techniques in Data Acquisition Triggering – DAQmx is a great resource for understanding how triggering works in DAQmx.

To perform an analog level trigger on your analog input line can be programmed below as below. Using the DAQmx Start Trigger (Analog).vi you can set the slope (Rising), the voltage level to trigger at (0.5 V), and the trigger source (Voltage). The trigger source can be either the PFI line or the Channel Name that was assigned with DAQmx Create Channel (AI-Voltage Basic).vi.

Finally, there are two examples that might prove useful. First there is a shipping example which can be found in the example finder by going to Help » Find Examples… in LabVIEW, then browse by task to Hardware Input and Output » Analog Measurement » Voltage » Acq&Graph Voltage-Int Clk-HW Trig Restarts.vi. The second example, DAQmx: Simple One-Channel Scope Using a DAQ Board, features some common oscilloscope functionality.

If you have any questions, please post back. Have a great day!

Message Edited by ryan_d on 10-04-2007 04:08 PM