Sources are modules that only generate data. The channels of instruments that are connected to the computer can be used as source, they generate the data that is measured by the hardware. The other source that is available is the software generator, which can create various signals from software that can be used in combination with measured signals.

Sinks are modules that only accept data. Typical sinks are e.g. graphs and meters, they accept data and display it. Other sinks are the disk writer, to store data to disk and the sound sink, to make data audible through the sound system of the computer.

I/O's are modules that accept data (Input), process this data in a specific way and then generate the processed data (Output). Data that is generated by an I/O can be used as input for a Sink or for another I/O. Multiple different I/O's can be chained to each other to perform a complex operation on the data. The Multi Channel software has many different I/O's to process data in a specific way. There are I/O's in several categories:

Basic math

These I/O's perform a basic mathematical operation on one or more signals:

I/O	function
add/Subtract	Add or subtract up to 32 signals
Multiply/Divide	Multiply or divide up to 32 signals
SQRT	Calculate the square root of a signal
ABS	Determine the absolute value of a signal
Differentiate	Differentiate a signal
Integrate	Integrate a signal
Log	Calculate the logarithm of a signal

More complex math

These I/O's perform a more complex mathematical operation on a signal or consecutive signals:

I/O	function
Gain/Offset	Apply gain and/or offset to a signal
Average	Outputs the average of n measurements
Low-pass filter	First order low-pass filter
Min/Max detector	Peak detection with optional fall-off
Limiter	Clip the input signal between a minimum and maximum limit
Resampler	Changes record length and sampling frequency of an input
Data collector	Appends small blocks of data to one big block

Analyzing I/O's

These I/O's analyze the input data and extract specific information from it.

I/O	function
FFT	Perform a Fast Fourier Transform (Spectrum analyzer)
Duty cycle	Determines duty cycle percentage
RPM	Converts a crankshaft sensor signal into Revolutions Per Minute
Pulse decoder	Decodes the A and B signal from a quadrature encoder to position
CAN analyzer	Decodes data on a CAN bus

All measurement setups in the Multi Channel software are built from one or more sources, I/O's and sinks. These are simply connected to each other by dragging and dropping. Multiple I/O's can be used to form complex mathematical operations.

In the image above, three I/O's are used to determine the area that is enclosed by two signals in XY mode.