Node Types¶

Connect I/O has five different types of nodes, Inputs, Outputs, Memories, Sources and Nodes:


Inputs	Values read from HOME I/O (e.g. light switch is on or off).
Outputs	Values written to HOME I/O (e.g. turn a ceiling light on or off).
Memories	Generic values exchanged with the simulation (read/write). For example, if the simulation is running, the current simulation date and time, etc.
Sources	Nodes for generating values (e.g. a Boolean, integer, float, string, etc.).
Nodes	Nodes providing functionalities (e.g. arithmetic operations, counters, connectivity with PLC and interface boards, etc.).

Inputs, Outputs, Memories¶

The first three types, Inputs, Outputs, and Memories, are tied together with HOME I/O and their names give you an idea of their purpose. To better understand these nodes, it helps to think of Connect I/O as a controller (much like a PLC or microcontroller). Inputs are used to read values, outputs to write values and memories to read or write values to or from the simulation.

Data Types¶

Input, output, memory and source nodes can hold values of different data types. The following table shows all the supported data types, equivalent IEC61131-3 and range.

Data Type	Range	IEC61131-3	Notes
Bit	True or False	BOOL	-
Byte	0 to 255	BYTE	-
Short	-32,768 to 32,767	SINT	-
Int	-2,147,483,648 to 2,147,483,647	INT	-
Long	-9,223,372,036,854,775,808 to 9,223,372,036,854,775,807	DINT	-
Float	-3.403 x 1038 to 3.403 x 1038	REAL	-
Double	±5.0 × 10−324 to ±1.7 × 10308	LREAL	-
String	64 UNICODE Characters	STRING	-
DateTime	00:00:00, January 1, 0001 through 23:59:59, December 31, 9999	DATE_AND_TIME	Represents an instant in time, typically expressed as a date and time of day.
Timespan	-10675199.02:48:05.4775808 to 10675199.02:48:05.4775807	N/A	Represents a time interval that is measured as a positive or a negative number of days, hours, minutes, seconds, and fractions of a second.

Addresses¶

Besides a value, each input, output, and memory have an address and name. The address is used to define where the value is stored, while the name helps to identify the node's value without having to keep track of the address. It's much easier to use names than numbers to identify a node. Commonly, when an I/O (input/output) and a name is grouped together it's called a tag. On the Nodes Palette, you can find a panel called Tags where all the simulation I/O points (with a name!) are automatically detected and have the name and address already set.

Note that Inputs, Outputs and Memories have an address range per data type. Bit address range is from 0 to 512 while for other data types is from 0 to 256.

Sources¶

Sources nodes generate values of any data type. Typically, these nodes are used upstream in the diagram and the generated values are set by the user.

BIT	Boolean value, click to toggle on/off.
BIT	Name: use it to describe this node.
NUMERICAL	Numerical value (byte, short, int, long, float or double). The value type is determined by the downstream socket to which it is linked to. For example, if the downstream socket requires an integer value, it will be cast to an integer. You set the value by typing it in the input field or by dragging the slider.
	Name: use it to describe this node.
	Max: maximum possible value.
	Min: minimum possible value.
STRING	Represents a string. Set the string value by typing it on the Value property.
	Name: use it to describe this node.
	Value: the string value.
DATETIME	A date and time value.
DATETIME	Name: use it to describe this node.
SYSTEM TIME	The current system (computer) date and time.
CYCLE TIME	The diagram cycle time in milliseconds, i.e. the time it takes to update the diagram.