Triggering a pulse after certain amount of time

[kaan13]

Hi everyone,

I am using cRIO, NI 9403 DIO and NI 9205 Analog Module. My controller's system time clock is 40 MHz. I am able to trigger two pulses at the same time but I want to trigger an analog signal after 25 nanoseconds a digital signal. For instance first the program generates a digital pulse and 25 nanoseconds after start of the digital pulse, analog pulse will be triggered.

How can I do this using LabVIEW FPGA?

I am new to LabVIEW so any ideas or any example VI's would be much appreciated.

Regards,

Kaan 

[GerdW]

Hi kaan,

first the program generates a digital pulse and 25 nanoseconds after start of the digital pulse, analog pulse will be triggered. How can I do this using LabVIEW FPGA?

Output your digital pulse. Then wait a tick (of your 40MHz clock), then output the analog "pulse"…

That said:

The NI9403 doesn't support 40MHz operation. It only allows upto 140kHz.

The NI9205 doesn't support 40MHz operation. It only allows upto 250kHz. It also is an AnalogInput module and does not provide analog outputs…

[kaan13]

Hi,

Thanks for your reply.

Output your digital pulse. Then wait a tick (of your 40MHz clock), then output the analog "pulse"…

I have a program in LabVIEW. I will also implement it in FPGA so most of the functions will be same. I have attached the picture. Could the program work as I want to generate two signals with 1 tick between their start time.  

It also is an AnalogInput module and does not provide analog outputs…

Sorry about the confusion I am thinking to use digital output of the NI 9205 analog module. There is one digital output on it.  

The NI9403 doesn't support 40MHz operation.

I am not going to generate pulses with 40 MHz frequency, I just need a gap for one tick between start of the analog module's pulse and digital module's pulse. 

[GerdW]

Hi kaan,

Could the program work as I want to generate two signals with 1 tick between their start time.

Surely not!

The FPGA doesn't need a stop button, nor does it support property nodes for FP elements.

Why do you need 2 loops?

I am thinking to use digital output of the NI 9205 analog module. There is one digital output on it.

NI doesn't specify the output propagation delay for that DO. Call the technical support and ask for specific numbers!

I just need a gap for one tick between start of the analog module's pulse and digital module's pulse. 

The NI9403 has a propagation delay spec of 330ns (max). (Did you read the specsheet?)

It will be a hard time to produce 2 pulses with ~25ns delay using your hardware…

[kaan13]

I changed the program to implement it on LabVIEW FPGA. The Mod3 (NI-9403) DIO1 produces single pulse that I can change frequency and pulse width.

As I understand due to NI 9403 has propagation delay spec of 330 ns(max) I am not be able to produce 2 pulses with 25ns delay and even delays which are smaller than 330 ns right?

I can produce 2 pulses with min 10 us delay using the program that I have attached. I am using an oscilloscope to monitor pulses. When I set delay time smaller than 10 us, the signals are generated at the same time.

I really don't understand why I can not set delay time smaller than 10 us. 

Regards,

Kaan