JYE Tech 062 - User Manual

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DN062-13v01

JYE Tech - 1 - www.jyetech.com

Fig. 1

Fig. 2

How to Use External Trigger

Appliable model: 062

1. Brief explaination of external trigger

Trigger is an important portion of a oscilloscope. It is used to synchrounize captures to generate stable waveform

displays and help to capture rarely appear signals. Most oscilloscopes contain a trigger that uses internal signal, i.e.

the signal being viewed, as trig source. Some oscilloscopes can use signal other than the one being viewed as trig

source, too. This is called external trigger.

For 062 digital storage oscilloscopes with firmware version of -080 or later the external trigger was implemented.

This design note explains how to use the external trigger. It includes connection of external trig signal, selection of

trig sources, and adjustment of trigger level.

2. Connection of external trigging signal

The point for external trig signal input is Pin 12 of J5. There are two ways to connect external trig signal.

1) Connect to pin 12 of J5 directly

through a 2K – 10K (1/4W)

resister. (see Fig. 1). The resistor

protects scope from being

damaged and can not be omitted.

2) Connect to the 500Hz Test

Signal output terminal. In order

to be able to do so pin 4 of J5

must be shorted to pin 12 of J5

(Fig. 2). When pin 4 and pin 12

of J5 are shorted the 500Hz test

signal output will be

automatically disabled as long as

external trig source is selected.

3. Selection of trig sources

After external trig signal is connected you

have to tell the scope to use it as trig source.

This is done by first pressing [LEVEL] to

highlight the trigger level indicator. Then

press [LEVEL] again to toggle trig source to

external. The little case letter above trigger

level indicator shows currently selected trig

source. “ i ” stands for internal trig. “ e “ for

external trig. Press [LEVEL] to make letter

“ e “ is displayed.

4. Adjustment of trigger level

Trigger level is a constant voltage that

determines at what level trigs are generated.

Since trigs are only generated when signal

level intersects with trigger level this

voltage need to be adjusted from time to

time. For 062 oscilloscope trigger level is

adjusted by pressing [ + ] and [ - ] buttons

while the trigger level indicator is

highlighted.

When external trig source is selected trigger

level adjustable range is 0V – 5V. The small triangle on the right border of the waveform window indicates trigger

level with its bottom position for 0V and top position for 5V. Please note t\hat external trigger level is independent

of internal trigger level and is not related to any shown waveforms. It is only a genearted voltage used to compare

with unshown external trig signal to produce triggings.

From the discussion above we know that in order to be able to generate trigging by an external signal the external

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Summary

External Trigger Signal Connection

Direct Connection with Resistor

Connects pin 12 of J5 directly via a protective resistor to prevent damage.

Connection to 500 Hz Test Signal

Connects to the 500Hz Test Signal output terminal, requiring pin 4 to be shorted.

External Trigger Level Adjustment

This document describes how to use the external trigger feature on the JYE Tech 062 digital storage oscilloscope, specifically for firmware versions -080 or later. The external trigger is a crucial function for oscilloscopes, enabling the synchronization of captures to produce stable waveform displays and to capture signals that appear infrequently. While most oscilloscopes use an internal signal (the signal being viewed) as the trigger source, the 062 also supports an external trigger, allowing a signal other than the one being viewed to act as the trigger source.

Function Description

The external trigger on the 062 oscilloscope allows users to trigger the device using an external signal, which can be particularly useful for synchronizing with external events or for capturing complex signals that are difficult to trigger internally. The trigger mechanism works by comparing the external trigger signal with a user-defined trigger level. When the external signal intersects this level, a trigger event is generated, initiating the waveform capture. This capability enhances the oscilloscope's versatility, enabling it to integrate more effectively into various test and measurement setups where external synchronization is required.

Usage Features

Connecting the External Trigger Signal: There are two primary methods for connecting an external trigger signal to the 062 oscilloscope, both involving Pin 12 of J5:

Direct Connection with Resistor: The most common method is to connect the external trigger signal directly to Pin 12 of J5 through a protective resistor. A 2K to 10K (1/4W) resistor is essential for this connection. This resistor serves a critical role in protecting the oscilloscope from potential damage and must not be omitted. This method provides a straightforward way to introduce an external trigger signal while ensuring the safety of the device.
Connection via 500Hz Test Signal Output: Alternatively, the external trigger signal can be connected by shorting Pin 4 of J5 to Pin 12 of J5. Pin 4 of J5 is typically used for the 500Hz Test Signal output. When these two pins are shorted, the 500Hz test signal output is automatically disabled as long as an external trigger source is selected. This method offers a convenient way to use the existing test signal output infrastructure for external triggering, provided the test signal is not needed simultaneously.

Selecting the Trigger Source: Once the external trigger signal is physically connected, the oscilloscope needs to be configured to use it as the trigger source. This is achieved through the following steps:

Highlight Trigger Level Indicator: Press the [LEVEL] button once to highlight the trigger level indicator on the display. This action prepares the oscilloscope for trigger source selection.
Toggle Trigger Source: Press the [LEVEL] button again. This action toggles the trigger source between internal and external. The currently selected trigger source is indicated by a small lowercase letter displayed above the trigger level indicator. An "i" signifies an internal trigger, while an "e" indicates an external trigger. To use the external trigger, ensure that "e" is displayed.

Adjusting the Trigger Level: The trigger level is a constant voltage that determines the point at which trigger events are generated. Since triggers are only produced when the signal level intersects with this trigger level, it often needs to be adjusted to suit the characteristics of the external trigger signal. For the 062 oscilloscope, the trigger level is adjusted as follows:

Highlight Trigger Level Indicator: Ensure the trigger level indicator is highlighted on the display.
Adjust Level with Buttons: Use the [+] and [-] buttons to increase or decrease the trigger level, respectively.

When an external trigger source is selected, the adjustable range for the trigger level is between 0V and 5V. A small triangle on the right border of the waveform window visually represents the trigger level, with its bottom position corresponding to 0V and its top position to 5V. It is important to note that the external trigger level operates independently of the internal trigger level and is not directly related to any waveforms displayed on the screen. It represents a generated voltage used solely for comparison with the unshown external trigger signal to produce trigger events.

For successful external triggering, the external signal (or at least a relevant part of it) must fall within the 0V to 5V range. Users should have some prior knowledge about the characteristics of the external trigger signal before connecting it. After connecting the signal, the trigger level must be appropriately adjusted to intersect with the signal to generate reliable triggers.

Maintenance Features

The primary maintenance consideration highlighted in the document pertains to the connection of the external trigger signal. The document explicitly states that a protective resistor (2K – 10K, 1/4W) is mandatory when connecting the external trigger signal directly to Pin 12 of J5. This resistor is crucial for protecting the oscilloscope from damage and "can not be omitted." This emphasizes a critical protective measure that users must adhere to during setup, effectively serving as a maintenance guideline to ensure the longevity and proper functioning of the device. Failure to use this resistor could lead to damage, necessitating repairs or replacement. Beyond this, the document focuses on operational procedures rather than routine maintenance tasks.