Can NI9425 receive a 100hz signal?

[knightlyu]

Hi Guys.

I  connect a 24V 100HZ signal to NI9425 Di 24. From the scope, I can see a clear 24 volts 100hz square waveform.

In the Labview, I change the NI9425 Di 24 variable from read to write and connect to a waveform chart. Then I get a random 1/0 waveform, mcuh less than 100HZ  and it's not a  sqaure waveform. By the way, I let the loop runs as quickly as possible and test the loop time which is less than 1ms.

I don't know what' wrong and it seems the FPGA has enough capability to receive a 100 hz signal from NI9425 datasheet.

[GerdW]

Hi lyu,

In the Labview, I change the NI9425 Di 24 variable from read to write and connect to a waveform chart.

Where does your data come from when both the NI9425 and the chart are data sinks? THINK DATAFLOW!

By the way, I let the loop runs as quickly as possible and test the loop time which is less than 1ms.

It's far easier to give recommendations when you provide your VI…

Which hardware do you use? The NI9425 is just a module, but where is it plugged in?

How do you write data to your DIO module?

[knightlyu]

Gred

The data comes from a controller and send to NI cRIO-9074 throuhg wire. I'd like to show you some screen shots for the waveform and dataflow for how to test the waveform later. However, I am not able to share the whole vi or attach anything. Sorry about that and thanks for your reply.