Changing Port Connection Properties
Port Connections are used to provide graphical access to signals defined within the schematic canvas, where the component instance resides. They provide a means to either read signals from, or output signals to the external system each simulation time step. Ports play an essential part in the construction of circuits in PSCAD, and are the graphical signal communication avenue between models.
To add aport connection to your component definition, the most straightforward method is to use the ribbon control bar Shapes tab:
Simply left-click the Port button on the ribbon bar, drag the connection to where you want it placed and left-click again.
NOTE: You may notice that port connections are always snapped to the graphic canvas drawing grid. This is to ensure that when other components are connected to yours, their respective connection points will overlap.
Port connection properties can be adjusted through the Port Properties dialog: Either left double-click or right-click over the connection and select Properties....
Data:
Name: Enter a name for the port connection. Note that this name must be compatible with standard Fortran naming conventions (i.e. it must begin with a non-numeric character, must not include spaces or other illegal characters, etc.).
Type: Select Electrical Node, Control Signal Input, or Control Signal Output.
Electrical Type: Select Fixed, Removable, Switched or Ground. This parameter is only enabled if the Type is Electrical Node (see the following Electrical Node Types section).
Control Signal Type: Select Logical, Integer, Real or Complex. This input defines the type of control data signal that will be passing through this connection and is based on the standard Fortran LOGICAL, INTEGER, REAL or COMPLEX declarations. It is only enabled if Type is Control Signal Input or Control Signal Output.
Dimension: If this connection is to carry an array signal, then this input specifies the dimension of the array. For example, if port connection N1 is to be defined as REAL N1(3), then this field should be specified as 3. You may also substitute the Symbol name of an integer input field or choice list in this field. The connection will assume a dimension equal to this value upon compilation.
Internal: Selecting this choice box disables the connectivity of the port, as well as the compiler warning message indicating that an internal electrical, isolated node exists.
Visibility:
Expression: Enter an expression to determine under what input conditions the object is to be visible. See Expressions Statements and Operators for more details.
When the port is selected as an electrical node, there are four types available to the user. These are described below:
Fixed: A fixed node is the most common type of electrical node and should be the default chosen when in doubt. It represents a simple electrical node.
Removable: A removable node is that which may be 'removed' by PSCAD, if it is to be part of a collapsible branch. For example, a branch with separate series RLC elements can be collapsed by PSCAD into an equivalent, single element impedance branch (Z) (effectively removing two extra nodes). Select removable if you would like to take advantage of this feature.
Switched: If your node is to be part of a frequently switching branch, that is a branch whose equivalent conductance is changing many times during a simulation (thyristor, GTO, etc.), then this option should be chosen. Switched nodes are included in the Optimal Node Ordering algorithm, which makes matrix decomposition more efficient, and thereby speeds up the simulation.
Ground: Select this option if your node is to be a ground node.