title: "ASA100 / ASA101A / ASA200 / ASA240 / ASA280 User Manual" subtitle: "Analog Signature Analyser" version: "V26007" date: "March 2026" lang: "English"

Notices

Copyright

© Electron Plus 2024-2026

This manual (or part thereof) may not be reproduced by any means (electronic or photographic, including translation into a foreign language) without prior written consent and agreement from Electron Plus as set-out in United Kingdom and international copyright laws.

Electron Plus is a trading style of Electron Plus Instruments Limited.

Part Number

ASA_EPIC_User_Manual.PDF

Issue

V26007, March 2026

Location

The latest version of this document can be found on our website:

www.electron.plus/manuals

Published By

Electron Plus Instruments Limited
Unit 8 Manor Farm Business Centre
Manor Lane
Stutton
Suffolk
IP9 2TD
UK

Hereafter referred to as Electron Plus.

Notes

• We frequently update our manuals and add new features and improvements as they become available, please ensure that you check our website for an updated version of this document, especially if updating your Electron Plus software.
• We make every effort to ensure the accuracy of this manual's contents. If you find any errors, have suggestions for expanding on a feature, or feel that we can improve its contents then please contact us at support@electron.plus
• Copying or reproducing this document or any part of this document without written permission of Electron Plus is strictly prohibited.

Trademark Acknowledgement

Electron Plus fully recognises and acknowledges any trademark(s) of the respective trademark holder.

Windows™ is a trademark of Microsoft Corporation.

Purpose of Manual

The purpose of this manual is to enable you to safely setup, configure and operate your Electron Plus instrument, associated software and/or accessories.

Please pay particular attention to any section with a warning symbol.

Safety Warnings

Warnings, cautions and notes are colour coded through-out this manual. These are divided into several categories and are described below:

::: warning WARNING - Pay special attention to anything written here - this is for your safety and continued protection and is critical information! :::

::: caution CAUTION - Damage may occur to your equipment or any DUT (device under test). :::

::: note NOTE - General text, with useful information or tips. :::

Introduction

What is the ASA?

The ASA (Analog Signature Analyser) is a diagnostic instrument designed for PCB-level fault finding using analog signature analysis (also known as V-I curve testing). It applies a test signal across two points of a circuit and displays the resulting voltage-current relationship as a characteristic signature (Lissajous pattern) on an oscilloscope-style display.

By comparing the signature of a known-good component or circuit node against the device under test (DUT), faults such as short circuits, open circuits, leaky components, and incorrect component values can be quickly identified — often without needing to know the circuit schematic.

Supported Instruments

Key Features

• Real-time V-I signature display
• Adjustable test voltage (200 mV to 10 V peak)
• Adjustable series resistance (50 ohm to 10k ohm, model dependent)
• Multiple test frequencies
• Signature comparison (overlay of reference and live traces)
• Automated test plans with pass/fail thresholds
• PCB image overlay with component location markers
• Euclidean distance matching for automated pass/fail
• Gate/bias generator for active-device testing (±10 V; ASA200/ASA240)
• MUX (multiplexer) channel selection (ASA240/ASA280)
• USB connection via FTDI

Getting Started

Installation

1. Install EPIC software from the provided installer or download from www.electron.plus
2. Connect your ASA instrument to the PC via USB
3. Install the FTDI USB drivers if prompted (the installer includes these)
4. Launch EPIC

Selecting the Instrument

1. Click the Settings button in the top ribbon
2. In the Instrument panel, select your ASA model (ASA100, ASA101A, ASA200, ASA240, or ASA280)
3. Click OK — EPIC will restart in ASA mode

Connecting

1. Ensure your ASA instrument is powered on and connected via USB
2. Click the Connect button in the top-left of the screen
3. EPIC will verify the USB connection and read calibration data from the instrument
4. When connected, the Connect button will change to show "Connected"

::: note If connection fails, check that the correct instrument model is selected in Settings and that the FTDI USB drivers are installed. :::

Operating Modes

The ASA software has three operating modes, selectable via the mode buttons in the top ribbon:

Basic Mode

Basic mode provides a simple, manual interface for probing individual components:

• A single large scope display fills the main area
• Use the Voltage, Resistance, and Frequency controls on the left ribbon to set the test signal
• Touch the ASA probes to the component under test
• The V-I signature is displayed in real-time on the scope
• Use Freeze to capture and hold the current signature for comparison
• Use Good / Bad to mark the component status

Auto Mode

Auto mode extends Basic mode with automated single-capture behaviour:

• The scope display operates as in Basic mode
• When a stable signature is detected, it is automatically captured
• Useful for rapid manual testing where you want hands-free capture

Advanced Mode

Advanced mode provides the full test plan interface:

• The main scope display shows the current test point signature
• Mini-scope displays show signatures from adjacent test points
• A test list on the right shows all test points with pass/fail status
• A PCB image overlay (if loaded) shows the physical location of each test point
• Test plans can be loaded, saved, and edited
• Automated test sequences can be run with Euclidean distance matching

Click the Advanced button in the top ribbon, or click the ADV mode button, to toggle Advanced mode.

Controls

Top Ribbon

Left Ribbon - Signal Controls

Voltage

Controls the peak test voltage applied to the DUT. Available values depend on the instrument model.

• Click + / - to step through voltage values
• Click the centre to cycle through all values
• Range: 200 mV to 10 V peak

Resistance

Controls the series resistance in the test circuit. Higher resistance provides better sensitivity for low-impedance components; lower resistance is better for high-impedance components.

• Click + / - to step through resistance values
• ASA100/ASA101A: 100 ohm, 1k ohm, 10k ohm
• ASA200/ASA240/ASA280: 50, 100, 200, 500, 1k, 2k, 5k, 10k ohm

Frequency

Controls the test signal frequency.

• Click + / - to step through frequency values
• Different frequencies can reveal different component characteristics (e.g., capacitance is more visible at higher frequencies)

Left Ribbon - Action Buttons

MUX Controls (ASA240/ASA280)

The multiplexer-equipped instruments (ASA240, ASA280) have MUX selection buttons to route the single signature engine to the active channel for testing.

Test Plans

Overview

Test plans allow you to define a sequence of test points on a PCB, each with its own test parameters and reference signature. In Advanced mode, you can step through the test plan, comparing each point against its stored reference.

Test plans are saved as .ept files (Electron Plus Test plan).

Creating a Test Plan

1. Switch to Advanced mode
2. Set the voltage, resistance, and frequency for the first test point
3. Touch the probes to the first component and capture a good reference signature
4. Mark it as Good
5. Move to the next test point and repeat
6. Save the test plan via Settings > Save Test Plan

Running a Test Plan

1. Load the test plan via Settings > Load Test Plan
2. Switch to Advanced mode
3. Click Auto Test to run through all test points automatically, or step through manually
4. Each point is compared against its stored reference using Euclidean distance matching
5. Results are shown as Good (green), Bad (red), Untested (yellow), No Signature (pink), or No Test (grey)

PCB Image Overlay

You can load a photograph of your PCB and mark the location of each test point:

1. In Advanced mode, load a PCB image via the test plan settings
2. Each test point can be assigned X/Y coordinates on the PCB image
3. The PCB image is displayed alongside the scope, with crosshairs showing the current test point location
4. This helps operators quickly locate the correct probe position on the physical board

Signature Interpretation

Basic Signatures

Comparison Testing

The most powerful use of analog signature analysis is comparison:

1. Capture a reference signature from a known-good board
2. Compare the same test point on the suspect board
3. Any difference in the signature shape indicates a fault

::: note Signature analysis does not require power to be applied to the board under test. The ASA provides its own low-voltage test signal, making it safe for unpowered testing. :::

Calibration

The ASA stores calibration data in the FTDI EEPROM on the instrument. Calibration is performed at the factory and should not normally need adjustment.

Calibration data includes:

• DAC gain and offset values for voltage output accuracy
• ADC gain and offset values for measurement accuracy
• DC bias calibration values

::: caution Do not modify calibration data unless you have the appropriate calibration equipment and procedures. Incorrect calibration can result in inaccurate measurements. :::

Troubleshooting

Specifications

Refer to the datasheet for your specific ASA model for detailed electrical specifications. Datasheets are available at:

www.electron.plus/documentation

Contact and Support

For technical support, please contact:

Electron Plus Instruments Limited
Email: support@electron.plus
Web: www.electron.plus