2.2 Electrical and electronic component manipulation in national

Component placement, rotation, selection and wiring

Placement, rotation, and selection

Once parts have been selected from their respective database, it is time to place them onto the schematic,and wire them together. Double-clicking on a component in the browser will attach that component to the cursor. This behavior isknown as“ghosting”. Ghosting helps guide users when placing components anywhere on the schematic by left-clicking at thedesired location.

Components can also be rotated while ghosting, and any time after placement. To rotate a part while ghosting,press Ctrl-R. Ctrl-R will also work when a placed component is selected. Placed components can also be rotated by right-clickingon them and selecting 90 Clockwise or 90 CounterCW.

To select a component, simply-left click on it. To select multiple components, click and drag to create aselection around the desired components. A dashed line indicates that a component is selected. Individual elements of a symbol canalso be selected, such as the component value and reference designator. To select these, left-click on the desired text orgraphic element.

Holding the Shift key while selecting allows multiple components to be selected or de-selected.

Components can be replaced by right-clicking on them then selecting Replace Component(s) from the right-clickmenu. Users can then select the replacement components from the newly opened component browser. Multisim will connect the newcomponent to the same nets as the original component.

Wiring

Multisim provides modeless operation—the action performed by the mouse cursor is dependent on the cursor’s location. There is no need to select a tool, or mode when workingwith Multisim. The cursor will change depending on what object is underneath it. describes the different icons that the mouse cursorwill display.

When the cursor is over a pin or terminal of a component, that component can easily be wired by left-clicking.When the cursor is over an existing wire and near a pin or terminal the net can easily be re-wired.

Left-click on the terminal to begin wiring, and to finish the wire, left-click on the destinationterminal.

When a wire is placed, Multisim will automatically assign it a net number. Net numbers increasesequentially, beginning with 1. Ground nets are always numbered 0—a requirement of the underlying SPICE simulator. To change a net number, or assign it a logical name instead, simply double-click onthe wire.

Autowiring by touching pins

Multisim also allows auto-connection of pins to wires, and pins to pins. To automatically connect a component toexisting nets or pins, simply place that component so that its pins are touching an existing net or pin.

Autoconnect passives

Multisim provides the ability to place a component in-line with an existing wire or set of wires. Toautomatically split an existing wire around a component, simply place that component in-line with the wire (Figure 6).