Analog Output Errors with PCI-6251 Driver in DasyLab 10.0

[Ryan Wight]

Hi,

I am having a great deal of issues in trying to set up a DasyLab sheet to generate a varying frequency train for my stimulator.

I have two different TTL generator pulses hooked up to the output and the recorder is showing the exact train I want to send out. However, when I view the ouput on my oscilloscope, nothing will show up.

Currently, I have the output task as a 1 Sample (On Demand) generation mode in MAX. If I change it to continuous samples, I get an error message in DasyLab explaining "the module can display the number of 'values to be written'".

If I change the TTL generator pulse options to a time base set-up "DasyLab" from "driver" I get a saw tooth pattern at a constant rate instead of the square wave pulses that I need.

Please Advise

[CJ_Butler__DASYLab_Pro]

It is all about timing and time bases.

The 1 sample per setting only updates once per block, typically.

Can you post your worksheet, and also tell me:

 - what operating system

 - what version of NI-DAQmx

 - What version and level of DASYLab? (e.g. DASYLab Full V11)

Thanks... .

[Ryan Wight]

We just upgraded to the DASYlab 11 pro, we were using DASYlab 10 basic, but are still getting the same issues.

Our NI-DAQ is the PCI-6251

We are using Windows XP

I attached the sheet, and if it doesn't work, there's also a screen shot to illustrate our set up

-Ryan

[CJ_Butler__DASYLab_Pro]

Ryan,

You're already working with Measurement Computing Application engineering... and they're in contact with me.

The fundamental issue is the output task -- the one sample mode is software paced, and not useful for outputting a waveform.

[Ryan Wight]

Agreed.

But if I change it to continuous samples I get an error message

[Ryan Wight]

"The module can process the number of 'values to be written'"

even if I change it to continuous, have 1k blocks and sample at 10k I still get the same problem

[TomRizzo]

Ryan,

I got some very good results with a MCC USB-1208HS-4AO.

Generating output is always been a problem with DAQ board of many brands.  Since MCC fixed their driver, I had great resuts compered to NI that I always get an error message eventually.

[CJ_Butler__DASYLab_Pro]

I set it up in simulation, and was able to drive a simulated output at 51KHz, using your input time base.

This device claims an output rate of MS/sec, so that I would expect 50KHz to be easy. Both the input task and the output task need to be set to Continuous and the same sample rate and samples to read. I used 10k for the samples to read, simply to update the output more frequently.

[Ryan Wight]

I changed the input task and the output tasks so that both are continuous, reading at 10k and rate is 50k.

I'm still receiving the same error message

-Ryan

[Ryan Wight]

Hi Tom,

Is the MCC USB-1208HS-4AO DAQ board comparable in its functionality to the NI-DAQ PCI-6251? If so, have you been able to send out 100Hz 5V TTL pulses and receiving them via oscilloscope?

Secondly, what is the pricing of that DAQ board

-Ryan