Placing and naming wires

The purpose of wires is to create connections. When you connect a wire to a pin, Capture provides visual confirmation: the unconnected pin box on the pin disappears. If two wires cross at 90 degrees, they are not electrically connected unless you create a junction by clicking on one wire as you draw the other to it, or by placing a junction over two crossing wires.
When a wire forms a "T" intersection with a pin or another wire, a visible junction is shown. If the two objects don't intersect, like when a wire ends at a pin or where the next wire begins, then a junction does not appear.
When you place a wire, it is assigned a system-generated net name. You can replace the system-generated name by assigning an alias or a net name. If you connect a wire to an existing net, the wire assumes the name of that net.

In this section:

To place a wire

1. From the Place menu, choose Wire.
   Or Press the W key on the keyboard.

2. Click on the schematic page to start the wire.
   You can press F6 to change the cursor to crosshair to start the wire from a specific location.
3. Use the mouse to draw the wire. Click to place a vertex and change directions. The vertex is constrained to multiples of 90 degrees.
4. If the wire ends at a pin or another wire, click to end the wire. The wire appears in the selection color.
   OR
5. Double-click to end the wire.
6. Select the selection tool to dismiss the wire tool.
   OR
7. Press the Esc key on the keyboard.

To place a non-orthogonal wire

• Hold down the Shift key while you draw the wire. There is no constraint on vertex angles.

To attach a wire to a net

1. Begin or end the wire on the net.
   OR
   Click as you draw the wire over the net.
   OR
   Create a net alias, as described below, assigning the alias of the net to this wire. Within a schematic page, wires with the same name or alias are electrically connected.

As you place buses and wires:

• A bus and a wire can be connected only by name.
  
  • If you begin or end a bus segment on a segment of a wire, a vertex is added to the wire and a junction appears, but the bus and wire are not electrically connected.
  • If you begin or end a wire segment on a segment of a bus, a vertex is added to the bus and a junction appears, but the wire and bus are not electrically connected.
  • If you begin or end a wire segment on a segment of another wire, a vertex is added to the second wire, and a junction appears—the wires are connected.
• Two buses or two wires can be connected physically.
  • If you begin or end a bus segment on a segment of another bus, a vertex is added to the second bus, and a junction appears—the buses are connected.

OrCAD recommends that you connect the pins of the parts using a wire, and avoid placing parts so that two pins meet end to end. This is because, parts with direct pin-to-pin connections produce a system-generated net name to establish the connection and:

• Capture will not allow you to assign your own net name in the place of the system-generated net name.
• Searching for the system generated net name can be difficult if you are not aware of the pin-to-pin connection.
• If you move the parts after creating the netlist, the system-generated net name might change. This may cause net name conflicts when you run back-annotation.

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