04-26-2011 06:36 PM
I am evaluating NI USB-6212 using LabView Signalexpress. Where can I find a
manual to play with the device. In the LabView SignalExpress manual, there is no instructions about how to use the device. I am looking for an instruction of how to generate a analog signal from a text file data.
04-27-2011 12:52 PM
Generating an analog output from a text file is easy to do in SignalExpress.
Step one: Load Text file data
In the project pane, add a Load from ASCII Task. This can be done by right clicking the project pane and selecting Load/ Save Signals>Analog Signals> Load from ASCII
Step two: Generate Analog Output
In the project pane, add a Generate Analog output. This can be done by right clicking the project pane and selecting Generate Signals>DAQmx Generate>Analog Signals> Voltage. Next, follow the one screen popup to select the 6212.
Hope this helps,
04-29-2011 01:22 PM
For 2 analog outputs, you can select both channels in the task. Another way would be to add a channel in the configurations tab for the analog output task. Make sure you only create 1 task per device otherwise you will see an error.
05-04-2011 04:09 PM
From USB6212, what is the best way to connect the attenuator to the analog output? It seems that 5 Kohms seris output impedance is assumed. For 1000:1 attenuation, should I connect 45Kohms and 50 ohms resistors?
05-05-2011 11:35 AM
You will want to run a 50ohm and 45kohm resistors in series on the output. you will get close to 1000:1 attenuation if you measure across the 50ohm resistor. You must also be sure that you are not pulling any load across the tapped wires from the 50ohm resistor, otherwise it will not act as a voltage divider as you intended it to be.
05-06-2011 11:21 AM
The specification sheet show that AO will drive up to 2mA, noramlly what happens is the current is limited to 2mA and the voltage will drop if the load impedence is too low. It is listed to have overvoltage protection up to 30V which will protect the board up to 30V if some external source is trying to drive the analog output. Normal shorts are not a big problem unless you are driving the output externally.
05-12-2011 11:23 AM
Is there a way to digitize the analog input signal and process it and send out as an analog output signal again? So it is a digital signal processing in between the analog signals.
05-13-2011 02:49 PM
When the analog signal is read into the data acquisition card it is being digitized into samples, and that is what SignalExpress is actually working with so anytime you useSignalExpress to acquire data, do some analysis and produce an output that digitizing is happening already. You can read about the input and output in the help manual. Hope this helps.