Set AI channel gains for a MCC USB-1808

[jwright70288]

Folks at MCC,

My name is Jim and I had a question about setting the channel gain for a MCC USB-1808 DAQ:

I am using a MCC USB-1808 DAQ unit on Linux and needed to configure gain ranges for 5 analog input channels.  Three of the AI channels are  “BIP10VOLTS” and 2 need to be set to “BIP1VOLTS”.  I had been using defaults from the example code (BIP10VOLTS) and starting acquisition using the “ulAInScan” function.

 

In order to be able to customize or set the gain range it looks like I need to use the channel descriptor data structure to set these. In addition, it appears that I have to use a different scan function (mode?) “ulDaqInScan” to scan the DAQ.

 

Is this a correct assumption?  Or is there some other way to configure the gain range and still use the “ulAInScan” function?

 

Can you tell me what the difference between is between the “ulAInScan” and “ulDaqInScan” functions in terms of transferring the buffer data (i.e getting the scan status and retrieving the buffer index from the scan transfer status)?  

 

Thanks for your help!

 

 

 

Edited January 30, 2023 by Fausto
Device is a MCC USB-1808.

[Fausto]

Hello @jwright70288.

You should use the ulAInLoadQueue() function in conjunction with the ulAInScan() function, for your analog input channels.

https://www.mccdaq.com/PDFs/Manuals/UL-Linux/c/1808.html

The 'ulDaqInScan()' function allows scanning of multiple input subsystems, such as analog, digital, counter, and stores the samples in an array.  This method only works with devices that support synchronous input.

Regards,

Fausto