Use the AES Trigger Pickup to sync your MODIS, VERUS, or Vantage Pro scope display to an ignition event. When attached to a plug wire, the AES Trigger Pickup will shape the signal into a clean pulse that your scope can use as a trigger.
Displaying a trigger signal on the screen is a very powerful aid for signal analysis, whether you need to judge the relationship of a signal to a position of the crank shaft or to an ignition event, or simply, just to hold/stabliize a repetitive signal. The pulse produced by the trigger pickup makes this possible.
Applications
Stepping through the Crank Signal: Many crank signals are very repetitive without any specific characteristic to trigger from. This results in a signal that walks left and right across the screen. Put the AES Trigger Pickup on #1 plug and trigger from it. The crank signal will now be stabilized. To step through the crank signal, move the Trigger Pickup to the next plug wire…and the waveform will update a new section of the signal!
Cranking Compression: Place the AES Trigger Pickup on #1 spark plug and perform a cranking compression test. The Trigger Pickup signal will represent #1 compression in the cranking compression waveform.
Exhaust Pressure Testing: Same as above. Use the AES Trigger Pickup signal to mark fire in the hole - #1.
The AES Trigger Pickup (Inductive) Lead is an 'external trigger' and connects to any scope channel, usually channel 1.
Snap-on scopes have an internal trigger, why do I need an external trigger?
The MODIS, VERUS, and Vantage Pro have a dedicated ignition trigger input that does not display the trigger signal, this can put you at a disadvantage. For example, when you slow the time base, if the trigger pulse is not visible it is difficult to judge when the next firing event occurs. With the trigger pulse on display you know exactly when it happens in relation to the other waveforms on display.
Seeing is believing! With a trigger pulse displayed on the scope you:
- can see the exact relationship between the trigger pulse and the other waveforms on display.
- will know when other signals are displayed according to the firing of #1 cylinder: For example, identify cylinders for cranking compression test or running cylinder contribution tests.
- can make adjustments to time base and still maintain the organization of the waveforms on the screen regardless time setting
- can use it as a reference point to correctly superimpose or parade a succession of individual events such as ignition signals even at slow time base settings.
Scope Setup
Instructions for setting your scope to display a firing event (trigger pulse) are included with the test lead.
Test Lead Configuration
The AES Trigger Pickup (Inductive) Lead is 10-ft long.
Connection to scope: The test lead is configured with two banana plugs (b-plug): The yellow b-plug inserts into any of the input channels. The black b-plug inserts into the input ground and is stackable to allow other channels to use the ground when using multiple channels.
Connection to vehicle: The test lead has one connection on the vehicle: Trigger pickup clamps around plug wire. A ground connection is not necessary since the lead is inductive.
Characteristics of the AES Trigger Pickup (inductive) Lead for Snap-on Scopes
(AES# 01-14-snap): |
| Attentuation: |
n/a |
| Connector at Scope: |
Signal: Stackable, Shrouded Banana Plugs Yellow
Ground: Stackable, Shrouded Banana Plugs Black |
| Cable: |
ST3, shielded |
| Color: |
Black |
| Length: |
10-ft (ask about custom lengths) |
| Connector(s) at vehicle: |
Trigger pickup onto plug wire |
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* What type of connector does my scope use?
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