Data Sheet

LABCENTER ELECTRONICS LTD.
26
Terminal connection
Power, Ground and NC terminals are the exception to this rule, although there is no
reason not to label them; an unlabeled power terminal is assigned to the VCC net
and an unnamed ground terminal will be assigned to net GND. A pin connected to
the NC terminal is NC and cannot then be connected on the layout.
Essentially what we are doing by labeling a terminal is making a connection to somewhere else
on the schematic (a terminal with the same name) without placing a physical wire between the
two objects.
As discussed previously, if you are in any doubt, Proteus is flexible enough to present you with
several methods for editing parts - choose your preferred method for editing the terminal from
the following:
Double left click on the terminal.
Right click on the terminal to select it and launch the context menu and then use the Edit
Properties menu option.
Enter Selection Mode, left click to highlight the terminal, then right click to launch its
context menu and use the Edit Properties menu option. Remember to exit selection mode
when you are finished.
Having now launched the terminals dialogue form, type in VDD in the edit field as shown below
and hit ok to exit the dialogue form.
Note that, where appropriate you should always prefix numerical terminal values with a '+'
or '-'. For example, a terminal labelled 12V is ambiguous and you should therefore ensure
it is labelled +12V or –12V.
Finish the job now by editing the other terminals and labeling them appropriately such that your
completed circuit block now looks like the following: