Preparing to probe a digital bus

Once you have installed the hardware and software, and developed a basic understanding of the ChronoVu probe hardware, you are ready to probe your bus.

WARNING: If you have not read the Cautions and Warnings page, please do so now before proceeding to the next step.

Connect the ChronoVu to your computer

Open the ChronoVu software and connect your ChronoVu probe to a USB port on your computer. If your computer does not recognize the ChronoVu device, please insure that the appropriate USB driver has been installed (see Installing the USB Driver for instructions). Once the ChronoVu has completed an internal power-up sequence, the red “idle” LED will light to indicate that the ChronoVu probe is ready to receive commands.

Connect the ChronoVu to the Device Under Test

The ChronoVu probes may be connected to the Device Under Test (DUT) while the DUT is running, however it is often advisable to connect the probes before powering the DUT to avoid causing logic faults in the DUT while attempting to connect the probes. The ChronoVu ground probe MUST be connected to a ground node on the DUT before any meaningful measurements can be made. Once the ground node is connected, the other eight ChronoVu probe inputs can be connected to appropriate nodes in the DUT circuitry. Unused ChronoVu probe inputs can be left floating (unconnected).

Select appropriate data acquisition settings

Open the Acquisition Setup menu in the ChronoVu software by clicking on the icon on the tool bar, or the Data Acquisition–>Acquisition Setup menu item from the menu bar. (see User Interface or Data Acquisition Setup for assistance).

Sample Rate

Choose an appropriate sample rate based upon your knowledge of the signals to be probed. If the signal characteristics are completely unknown, use the fastest signal rate available (0.01us for LA8 and 0.005us for LA16)). Once the initial data has been acquired and processed, the sample rate can be adjusted, and the data reacquired as needed. (See Understanding the ChronoVu digital signal probe or Data Acquisition Setup for assistance).

Trigger Selection

Choose a signal state that will trigger the beginning of the desired data window. Your ChronoVu device will monitor the data bus until the trigger condition is observed. Once the trigger condition has been met, the ChronoVu probe will collect a data window surrounding the trigger position (8Msample for LA8 or 4Msample for LA16). (See Understanding the ChronoVu digital signal probe or Data Acquisition Setup for assistance).

Visual preferences

If desired, new colors and names can be given to each probed signal, unused signals can be made invisible, etc. (Note that data for all channels will be acquired and stored in the data file, even if the visibility of the channel is not enabled.) See Data Acquisition Setup for assistance.

Select OK

Once you have closed the Data Acquisition Setup menu, you are ready to acquire your first sample set. Data Acquisition settings can be further adjusted at any time by reopening the Data Acquisition Setup menu. Data Acquisition Setup parameters may also be saved to a file for later retrieval. (See Saving and Loading Files for assistance).