Invalid Count error with USB-1608FS Plus

[KLambert]

Hello,

We have been using the USB 1608FS DAQ for data acquisition successfully for years and have recently began trying to use the USB-1608FS plus unit. 

Since changing to the 1608FS Plus in the exact same set up without any changes to the code we have encountered an ‘invalid count’ error.  Having read the universal library help instructions we haven’t managed to solve the problem so I am hoping you may be able to shed some light on how we can go about solving this problem to get the unit working. Ideally, we want the 1608FS Plus to operate in the same way as the 1608FS.

The following function is creating the error;

ULStat = DaqBoard.AInScan(startchan, stopchan, numsamples, ref frequency, Range, MemHandle, Options);

Startchan =3

Stopchan = 5

Numsamples 32768

Frequency = 10000

Range = MccDaq.Range.Bip10Volts

MemHandle = MccDaq.MccService.WinBufAlloc( 32768);

Options = 0

This works with the 1608fs but ‘invalid count’ count error occurs with the 1608fs+.

Please let me know if you need any more information on the problem and I look forward to your response.

[Fausto]

Hello @KLambert.

Were both devices connected to the same host system and detected in InstaCal or did you swap device connections to the USB port between tests?

What is the serial number and usage history of the USB-1608FS-Plus?

Please test your USB-1608FS-Plus device with the UL examples: ULAI02, ULAI03, and ULAI06.  Do you get the same error?

 

 

Regards,

Fausto

[Fausto]

Is there a reason why you set the number of samples to the device's FIFO size?

Since you only specified 3 analog input channels, set the number of samples to be divisible by 3, i.e. 32,766 samples.  Does that number work for you?

[KLambert]

Hi Fausto,

We independently ran each board separately each time we checked them , restarting Instacal so it is not that issue. The unit is a brand new unit, I will have to check the serial number and get back to you.  We have also already tested the UL examples.

We will try reducing the sample no. from 32768 to 2766 and see if this works.  We use 32,768 as it is the max capability of the board and haven't had issues using this number previously with the USB-1608FS.

Cheers,

Kerr