Logic Analyzer Probe
A single-input tap that samples one node on the canvas and streams its value to a channel of the Logic Analyzer (Tools menu). It performs no logic and drives nothing back onto the circuit — wiring a Probe's input to a node never changes that node's behavior, it only observes it. Place up to 16 probes, one per channel; each one renders in the analyzer's timing diagram in the probe's own color, so you can tell which trace belongs to which node at a glance.
Watching a single signal
Drop a Probe and wire its input to any node — a switch output, a gate output, anything you want to watch. Open Tools > Logic Analyzer and press Run: the probe's channel appears in the panel and starts tracing the node's value live, colored to match the probe on the canvas.
One probe per channel, up to 16
Each Probe you place becomes its own channel in the Logic Analyzer panel, where it can be renamed, recolored, or muted without touching the wiring on the canvas. The panel only has room for 16 channels; if you place more probes than that, only the first 16 show up, so remove ones you no longer need before adding new ones.
Comparing timing across a circuit
Wire one Probe to a Clock's output and three more to the outputs of a 4-bit Counter it drives. Running the simulation scrolls all four traces together in the Logic Analyzer, letting you read the counter's binary sequence directly off the clock edges — the same technique used to debug propagation delay and race conditions in real hardware.
Citations
- Wakerly, J. F. (2018). Digital design: Principles and practices (5th ed.). Pearson.. Reference 1
- Mano, M. M., & Ciletti, M. D. (2018). Digital design: With an introduction to the Verilog HDL, VHDL, and SystemVerilog (6th ed.). Pearson. Reference 2