Documentation - Sequences - Industrial Test Sequencer

Overview

Test sequences in SeqMaster are defined using YAML or JSON files. Each sequence consists of metadata, configuration, and a series of steps that are executed in order. Sequences can include measurements, actions, flow control, and operator interactions.

Key Concepts

• Steps - Individual test operations (measure, action, prompt, etc.)
• Groups - Logical grouping of related steps
• Property Sets - External limit files for different product variants
• Variables - Dynamic values that persist across steps
• Flow Control - Conditional execution and loops

YAML Format

Sequences are typically written in YAML for readability. Here's the basic structure:

pcb_functional_test.yaml

name: PCB Functional Test
version: "1.0.0"
description: Complete functional test for PCB Rev A

metadata:
  author: John Smith
  created: "2024-01-15"
  part_number: PCB-001-A

config:
  timeout: 300  # seconds
  stop_on_fail: false
  property_set: pcb_rev_a_limits.yaml

steps:
  - id: init_dmm
    name: Initialize DMM
    type: setup
    driver: keysight_34461a
    config:
      mode: DC_VOLTAGE
      range: 10

  - id: measure_vcc
    name: Measure VCC
    type: measurement
    driver: keysight_34461a
    action: read
    limits:
      low: 4.8
      high: 5.2
      unit: V

Step Types

SeqMaster supports several step types for different operations:

setup

Initialize and configure hardware before measurements.

- id: setup_psu
  name: Configure Power Supply
  type: setup
  driver: rigol_dp832
  config:
    channel: 1
    voltage: 12.0
    current_limit: 1.0
    output: true

measurement

Take measurements and compare against limits.

- id: check_current
  name: Measure Quiescent Current
  type: measurement
  driver: keysight_34461a
  action: measure_current
  limits:
    low: 0.001
    high: 0.050
    unit: A
  store_as: quiescent_current  # Save to variable

action

Perform actions without measuring (toggle, send command, etc.).

- id: toggle_relay
  name: Connect Load
  type: action
  driver: test_fixture
  action: set_relay
  params:
    relay: K1
    state: true

prompt

Request operator input or verification.

- id: verify_led
  name: LED Verification
  type: prompt
  message: "Is the green LED blinking?"
  options:
    - label: "Yes"
      value: pass
    - label: "No"
      value: fail
  timeout: 30

script

Execute custom Python code for complex operations.

- id: custom_calc
  name: Calculate Efficiency
  type: script
  code: |
    input_power = vars['input_voltage'] * vars['input_current']
    output_power = vars['output_voltage'] * vars['output_current']
    efficiency = (output_power / input_power) * 100
    
    result.value = efficiency
    result.passed = efficiency >= 85
    result.message = f"Efficiency: {efficiency:.1f}%"

delay

Wait for a specified duration.

- id: stabilize
  name: Wait for Stabilization
  type: delay
  duration: 2.5  # seconds

Variables

Variables allow you to store and reuse values across steps. They can be defined at sequence start, captured from measurements, or set via scripts.

Using Variables

variables:
  board_type: "rev_a"
  test_voltage: 5.0
  max_retries: 3

steps:
  - id: measure_v
    name: Measure Voltage
    type: measurement
    driver: dmm
    action: read
    store_as: measured_voltage  # Store result
  
  - id: calc_error
    name: Calculate Error
    type: script
    code: |
      expected = vars['test_voltage']
      actual = vars['measured_voltage']
      error = abs(actual - expected) / expected * 100
      result.value = error
      result.passed = error < 5  # 5% tolerance
  
  - id: show_result
    name: Display Result
    type: prompt
    message: "Measured: ${measured_voltage}V"  # Variable interpolation

Flow Control

Control sequence execution with conditions, loops, and groups.

Conditional Execution

- id: extended_test
  name: Extended Burn-in
  type: group
  condition: "vars['board_type'] == 'military'"
  steps:
    - id: temp_cycle
      name: Temperature Cycling
      # ... steps only run for military boards

Loops

- id: channel_test
  name: Test All Channels
  type: group
  loop:
    variable: channel
    values: [1, 2, 3, 4]
  steps:
    - id: test_ch_${channel}
      name: Test Channel ${channel}
      type: measurement
      # ...

Retry on Failure

- id: flaky_test
  name: Communication Check
  type: measurement
  driver: serial_device
  retry:
    count: 3
    delay: 1.0  # seconds between retries
  # ...

Property Sets

Property sets allow you to externalize test limits and parameters. This enables using the same sequence for different product variants with different specifications.

pcb_rev_a_limits.yaml

name: PCB Rev A Limits
description: Standard limits

properties:
  vcc_min: 4.8
  vcc_max: 5.2
  current_max: 0.5
  temp_min: 0
  temp_max: 70

pcb_rev_b_limits.yaml

name: PCB Rev B Limits  
description: Extended range

properties:
  vcc_min: 4.5
  vcc_max: 5.5
  current_max: 0.8
  temp_min: -40
  temp_max: 85

Using Property Sets in Sequences

config:
  property_set: "${PROPERTY_SET}"  # Selected at runtime

steps:
  - id: check_vcc
    name: VCC Measurement
    type: measurement
    limits:
      low: "${props.vcc_min}"   # From property set
      high: "${props.vcc_max}"  # From property set
      unit: V

Complete Examples

complete_functional_test.yaml

name: Complete Functional Test
version: "2.1.0"
description: Full production test for Widget PCB

metadata:
  author: Test Engineering Team
  created: "2024-06-01"
  part_numbers:
    - PCB-WIDGET-001
    - PCB-WIDGET-002

config:
  timeout: 600
  stop_on_fail: false
  property_set: widget_limits.yaml
  required_hardware:
    - keysight_34461a
    - rigol_dp832
    - test_fixture

variables:
  test_mode: "production"

steps:
  # === SETUP PHASE ===
  - id: setup_group
    name: Hardware Setup
    type: group
    steps:
      - id: init_dmm
        name: Initialize DMM
        type: setup
        driver: keysight_34461a
        config:
          mode: DC_VOLTAGE
          range: AUTO
          
      - id: init_psu
        name: Configure Power Supply
        type: setup
        driver: rigol_dp832
        config:
          channel: 1
          voltage: 5.0
          current_limit: 1.0
          output: true
          
      - id: wait_power
        name: Wait for Power Stabilization
        type: delay
        duration: 1.0
  
  # === POWER MEASUREMENTS ===
  - id: power_tests
    name: Power Rail Tests
    type: group
    steps:
      - id: measure_vcc
        name: VCC Rail
        type: measurement
        driver: keysight_34461a
        action: measure_dc_voltage
        limits:
          low: "${props.vcc_min}"
          high: "${props.vcc_max}"
          unit: V
        store_as: vcc_measured
        
      - id: measure_3v3
        name: 3.3V Rail
        type: measurement
        driver: keysight_34461a
        action: measure_dc_voltage
        limits:
          low: 3.2
          high: 3.4
          unit: V
        store_as: v3v3_measured
        
  # === FUNCTIONAL TESTS ===
  - id: func_tests
    name: Functional Tests
    type: group
    steps:
      - id: comm_test
        name: Communication Test
        type: action
        driver: test_fixture
        action: send_command
        params:
          command: "*IDN?"
          expected: "WIDGET"
        retry:
          count: 3
          delay: 0.5
          
      - id: led_check
        name: LED Verification
        type: prompt
        message: "Verify green LED is blinking"
        options:
          - label: "Pass"
            value: pass
          - label: "Fail"
            value: fail
        timeout: 30
  
  # === CLEANUP ===
  - id: cleanup
    name: Test Cleanup
    type: group
    always_run: true  # Runs even if test fails
    steps:
      - id: power_off
        name: Turn Off Power
        type: action
        driver: rigol_dp832
        action: output_off
        params:
          channel: 1

Test Sequences