Avoiding synchronisation pulse when outputting data from an NI 9260

[Sendai-Jin]

Hi!

I've been fighting for few days with a cRIO equipped with a NI 9260 module for analog output. As I'm using it to drive piezoelectric actuators, I really must avoid any pulses, and I successfully cleaned up my code to get the output back to zero before exiting Data Mode. However, I still get a very short pulse when I'm starting Data Mode, of less than 0.2 ms but at least 0.5 V high.

After searching on NI database, I found out this seems to be a normal behaviour: https://zone.ni.com/reference/en-XX/help/373197L-01/criodevicehelp/9260_reading_data/

It says: "Wire a Boolean constant set to TRUE to the Startinput of the FPGA I/O Node to send a synchronization pulse to the module."

I would like to get rid of this, as this translates to a loud pop on my piezo actuator! Any suggestions on how to avoid this?

Thanks in advance for your help!

[AlexSim · Accepted solution]

Hi Sendai-Jin,

Following the link and the information you have given, it seems like it is not possible to disable the glitch a the beginning of the Data Mode.

Here you can see in the Datasheet that it's a normal behavior and it can not be disabled.

https://usermanual.wiki/Collections/National-Instruments/376926a_02.pdf

If you have a customer number you can maybe contact the commercial service to identify which card is more suitable for your application.

Kind regards,

Alexandre

[Sendai-Jin]

Thanks a lot, Alexandre!

This is quite difficult to find such information, which happen to be critical in my case. Unfortunately, the NI-9260 is the only module for analog output with 24 bit resolution... I'm considering using a digital output and some electronic circuitry to switch the output signal on and off...

It's too bad also that we can't set the power-on and/or startup states on this module...

Thanks again,

Regards.