Interpretation of the measured values of an analogue input

[MJ0082]

Hello,

I am completely new into programming with the UL. I program in C# and have implemented the sample program ULAI02 one-to-one. So I am reading out analogue inputs. The device i am using is the USB-1616FS

Now I am wondering how to interpret the values (ushort) in "ADData". I get values in the range 50000 while a voltage of 2.5V is applied to the analogue input, about 60000 when a voltage of approx. 4.5V is applied. Unfortunately, I can't find the connection.

Many thanks in advance.

[Fausto]

Hello @MJ0082.

The Universal Library (UL) Help is a good resource for developers to utilize when programming. 

https://www.mccdaq.com/pdfs/manuals/Mcculw_WebHelp/ULStart.htm

The USB-1616FS has a 16-bit A/D converter for 65,536 integer count values.  Given your two data points, you must have the analog input range set to +/-5 V.  The integer count is 0 at -5 V and 65535 at +5 V.  Check your wire connections and do not leave any input channels open.

Since the USB-1616FS does not support SCALEDATA, the UL examples display integer count values, not voltage values. 

 

 

For the USB-1616FS, you will need to use WinBufToEngArray() function to convert integer values to engineering unit values.

 

Edited June 5, 2023 by Fausto
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