ni 9263 voltage output

[meizhe143]

Hi All,

I am using Ni 9263 to generate square wave. I just modified the examples in the Labivew forders.

It is very similar. I use oscilloscope to watch the output.

Everything is ok except the voltage output. No matter how I change the amplitude in the host Vi, the indicator in FPGA vi shows  that the change go into effect, but the voltage in oscilloscope keeps 10 volts. All the four output have the same problems.

I attached my project and a figure to illustrate my problems,

Thanks for your kind help.

Jerry

[meizhe143]

by the way, the chassis is 9014 and the controller is 9104

Thanks

[StephenB]

your io node is configured for fixed point (FXP) values which are in engineering units of voltage (like -10 to 10 volts) but your square wave express VI is outputting the voltage as unscaled raw ADC counts (like -32k to 32k).

you can right click the module in your project and change its io node setting to raw adc counts.

[meizhe143]

Hi Stephen,

Thanks for your reply, Actually, units of voltage is just my input. I already used convert VI to translate it into raw ADC counts.

The problems is the input of IO node could change from -32k to 32k (you can see from the picture). But it didn't reflect the voltage change(it is always 10 volts) when I use oscilloscope to watch the 9263 IO output.

[meizhe143]

Hi Stephen,

Thanks for your reply, Actually, units of voltage is just my input. I already used convert VI to translate it into raw ADC counts.

The problems is the input of IO node could change from -32k to 32k (you can see from the picture). But it didn't reflect the voltage change(it is always 10 volts) when I use oscilloscope to watch the 9263 IO output.

[StephenB]

That's because you're converting on the host side but not on the FPGA code. See the attached picture i16 to FXP

You can either:

1. Convert the I16 to FXP on the FPGA
2. Change the IO node to be in "raw" I16 mode so you can avoid the conversion entirely. See attached picture raw mode. Then your IO node will be an I16 instead of FXP

Id recommend #2. It is easier and uses less resources