Sampling rate of DAQ device USB 1608GX

[nil1451]

the sampling rate of the device is 500 KHz. what is sampling rate for single channel? how does sampling rate per channel vary with chnage in number of channels in use ? and What is performance difference between single channel or differential input channel?
 

[DAQman]

The USB-1608GX is a multiplexed device, which means there is a single A/D converter for all the channels. The channels you specify are selected one by one for the A/D measurement. Divide 500 kHz by the number of specified channels to figure the maximum sample rate. 

There is no difference between differential and single-ended inputs when figuring sample rates. However, a differential input is better for noise and common mode voltage rejection. Noise tends to be on both wires, which is removed by a differential input. If you have a small ground loop between channels, it appears as a common mode voltage, which again is removed by the input.

[nil1451]

On 5/22/2024 at 7:47 PM, JRys said:

The USB-1608GX is a multiplexed device, which means there is a single A/D converter for all the channels. The channels you specify are selected one by one for the A/D measurement. Divide 500 kHz by the number of specified channels to figure the maximum sample rate. 

There is no difference between differential and single-ended inputs when figuring sample rates. However, a differential input is better for noise and common mode voltage rejection. Noise tends to be on both wires, which is removed by a differential input. If you have a small ground loop between channels, it appears as a common mode voltage, which again is removed by the input.

Do I need prior noise filtering in case I am going with single ended connections as opposed to differential inputs ? Is it possible to do differential input connections for the signals prone to more noise in order to accommodate more sensor output signals at a time?

[DAQman]

If the signal is noisy, the simplest thing to do is add an RC network. For example, adding a capacitor with a series resistor would provide a low-pass filter whose frequency cutoff is set by 1 / (2 * PI * R*C). https://www.electronics-tutorials.ws/filter/filter_2.html

The USB-1608GX can be set to have only differential or single-ended inputs. It's not possible to mix and match some differential and some single-ended.