What Is Automated Test Equipment (ATE)

What Is ATE with TofuPilot

Automated test equipment (ATE) is a system that tests a device without manual intervention. It applies stimuli, measures responses, and makes pass/fail decisions based on predefined limits. This guide covers what ATE involves, how modern Python-based ATE compares to traditional systems, and how to log ATE results with TofuPilot.

What ATE Includes

An ATE system has four layers:

The device under test (DUT) or unit under test (UUT) sits in the fixture. The test executive runs the sequence. Instruments measure. Software records.

Traditional ATE vs Python-Based ATE

Python-based ATE uses the same instruments and fixtures. The difference is the software stack. You replace proprietary test executives and data systems with open-source tools and TofuPilot.

Prerequisites

• Python 3.10+
• OpenHTF installed (pip install openhtf)
• TofuPilot Python SDK installed (pip install tofupilot)

Step 1: Define the Test Sequence

Each test step becomes an OpenHTF phase. The test executive runs them in order, collects measurements, and determines pass/fail.

import openhtf as htf
from openhtf.util import units


@htf.measures(
    htf.Measurement("supply_current_mA")
    .in_range(minimum=90, maximum=110)
    .with_units(units.MILLIAMPERE),
)
def phase_power_up(test):
    """Apply power and measure supply current."""
    test.measurements.supply_current_mA = 101.3


@htf.measures(
    htf.Measurement("output_frequency_Hz")
    .in_range(minimum=999000, maximum=1001000)
    .with_units(units.HERTZ),
)
def phase_frequency_check(test):
    """Measure output frequency against specification."""
    test.measurements.output_frequency_Hz = 1000250


@htf.measures(
    htf.Measurement("self_test_result").equals("PASS"),
)
def phase_self_test(test):
    """Command the DUT to run its built-in self-test."""
    test.measurements.self_test_result = "PASS"

Step 2: Connect to TofuPilot

TofuPilot replaces the proprietary database that traditional ATE systems use. Every test run uploads automatically with measurements, limits, and pass/fail status.

from tofupilot.openhtf import TofuPilot

test = htf.Test(
    phase_power_up,
    phase_frequency_check,
    phase_self_test,
)

with TofuPilot(test):
    test.execute(test_start=lambda: input("Scan DUT serial: "))

Step 3: Track ATE Performance

TofuPilot tracks ATE results automatically. Open the Analytics tab to see:

• First pass yield per test procedure and station
• Measurement distributions with limit overlays
• Failure Pareto showing which test steps fail most
• Station throughput (units per hour)
• Station comparison to catch fixture degradation or instrument drift

This data replaces the custom reports that traditional ATE software generates. It's available across all stations in real time.

ATE Architecture Patterns

TofuPilot supports all patterns. Each station runs its own test script and uploads results independently. The dashboard aggregates data across stations, lines, and factories.