How to use the Haltech ECU Oscilloscope: A Basic Guide

The oscilloscope function is a feature on current Haltech Elite or Nexus ECUs that can visually display electrical signals in the NSP software, showing how they change over time. This is very handy if you want to view, measure, and compare electronic signals coming from sensors that are read by the ECU. Think of it as a software-based ruler for electric waveforms. Here’s a basic guide on how to use it.

Getting Started with the Haltech ECU Oscilloscope

1. First, you need to install the Haltech NSP software on your tuning computer if you haven't done it already. The NSP software can be downloaded from the Haltech website by clicking on this link.
   
2. Use the included USB cable to connect your Haltech ECU to your computer. Ensure your car's ignition is on but the engine is not running yet.
   
3. Launch the Haltech software and navigate to the oscilloscope tool. 

Oscilloscope settings

Channel 1-4: Selects the channels you want to monitor. Typical channels include Trigger voltage, Home voltage, Ignition or Injector output voltage, SPI voltage, etc..

Scale: Controls the vertical scale of the display. This setting adjusts how much voltage each vertical division (horizontal grid line) on the screen represents. For example, if it's set to 1 V/div, each division represents 1 volt. Adjust the voltage scale depending on the type of signal that you are expecting. Say, if you're wanting to view the signal coming from a sensor that sends out a 12v square wave, then you'd typically match the voltage scaling to use 10v/div or 5v/div, so it displays correctly on the screen. Setting it too low, say 1v/div will make the oscilloscope display the signal too tall, leaving little screen space for the other channels to use. 

Y-offset: These slide bars adjust the vertical offset of all the four channels displayed in relation to each other. This is handy when comparing two or more signals to clearly see the signal edges in correlation to one another.

Trigger channel: This as an additional tool that helps you control when and how the oscilloscope starts to display the waveforms.

Trigger threshold: The value of the chosen Trigger channel that the oscilloscope will look at, before it starts to display the waveforms.

Trigger mode:

Auto: Continuously updates the display regardless of the chosen trigger channel threshold.

Normal: This mode will update the display whenever the trigger threshold occurs. The rising edge sub-mode will trigger the oscilloscope when the threshold is met coming from a lower value. The falling edge sub-mode will trigger the oscilloscope when the threshold is met coming from a higher value.

Single: This mode will update the display only once when the first trigger threshold occurs. The rising edge sub-mode will trigger the oscilloscope when the threshold is met coming from a lower value. The falling edge sub-mode will trigger the oscilloscope when the threshold is met coming from a higher value.

Trigger horizontal position: This slide bar allows you to adjust where the waveform centers based on the time when the trigger threshold occurs. The "T" mark at the bottom of the oscilloscope screen defines where this center will be.

Force Trigger: This button overrides all the trigger settings above; the oscilloscope will start displaying waveforms immediately upon clicking the button, thereby allowing the user to bypass any previously configured parameters, which might have been set for specific conditions, and ensuring that real-time data is shown without delay.

Time base: Controls the horizontal scale of the display. This setting adjusts how much time each horizontal division (vertical grid line) on the screen represents. For example, if it's set to 50 ms/div, each division represents 50 milliseconds. Typically, setting the Time Base will depend on the current RPM the engine is running at when you want to view the signal. When the engine is idling at around 900 RPM, setting the time base to 50 ms/div will give you a good view of one cam revolution (one engine cycle) worth of signal information.

Show Channel 1-4: Toggles the use of individual channels on or off.

Show Time Cursors: This feature provides two vertical cursors that can be moved left or right to measure the waveform and show the time difference between two events on the display.

Start Logging to PC (F6): This feature allows the scope trace to be captured in a PC log using NSP, which can be played back at a later time.

Run scope: Toggles the oscilloscope to pause and un-pause.