The simplest output device for digital circuits is the "Digital Output" with the keyboard shortcut O. A digital probe device does the same function. All input and output port logic levels are shown in the input and output ports in hexadecimal notation. For single wire probes, the probe values 1 and 0 mean logical High and logical Low. The value ? means indeterminate, i.e. the program cannot determine the signal value. A strength of S is a strong signal, strength R is for resistive strength, Z for High Impedance, and ? for unknown strength.
If "Circuit Animation" is activated for digital simulation, you will see the logical state of all wire during a simulation as text. If "Circuit [[Animation]]" is turned off, you can view the logic level and strength of any wire in the schematic window by using the "Probe Tool". You can access this tool either from the [[Schematic toolbar|Schematic Toolbar]] or from Edit Menu or simply using the keyboard shortcut Ctrl+Alt+P. In the "Probe Mode", place the tip of the logic probe on any wire and depress the left mouse button to see its logic level and strength. If the logic probe is probing a digital bus, then the value of the bus is the hexadecimal value calculated by making bit 0 of the bus the least significant bit.
For output devices, the device name and decimal or hexadecimal format can be edited. Choose "Assert High" or "Assert Low" to determine the polarity setting of the device.
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<b>Running a [[Digital Simulation]] as a Transient Test</b>
A live simulation is indeed a perpetual (time-domain) transient simulation. If your digital input values are known in advance as a function of time or time step index, you can alternatively run a transient test of your digital circuit. In this case, you need a digital source as your input. You can use one ore more digital probes for the output. The results will appear as timing diagrams in a graph window at the end of the transient test.