Functional Testing (FCT)
Verify how the assembled board responds under specified operating conditions. Agree the power, loads, firmware, interfaces, limits and records that define a meaningful functional pass.
Test what the assembly is required to do.
Functional testing applies defined operating conditions and evaluates the assembly’s response. A test setup may combine measurement instruments, generated signals, communication interfaces and an automated sequence to check the required behavior. [S30]
For a GlobalWellPCB project, replace a vague instruction such as “power on and check” with a requirement list. Describe the modes to exercise, the expected outputs, the permitted limits and the configuration that makes each result valid.
Translate operating requirements into test cases.
These are suggested test-plan categories, not a preconfigured service or a promise that every interface can be exercised without additional engineering.
Scroll the table horizontally to see all columns.
| Review area | What to evaluate | What to agree |
|---|---|---|
| Power and startup | Input conditions, startup behavior, current limits and required initial states. | Define the safe connection sequence and response to an abnormal condition. |
| Power outputs and loads | Required rails or outputs under the agreed load conditions. | State the load profile, measurement points, settling time and limits. |
| Digital interfaces | Required communication commands, responses and accessible I/O behavior. | Identify protocols, connected devices, timing and error conditions to exercise. |
| Analog or sensor paths | Specified stimulus and measured response over the required operating points. | Supply tolerances, reference conditions and any calibration procedure. |
| Firmware and configuration | Approved software build, version readback, options and required stored parameters. | Separate programming success from verification of product behavior. |
| Product-level operation | Applicable indicators, relays, connectors, peripherals or assembled-system functions. | Identify which hardware must be present and which behaviors are outside the production test. |
Tell us which features need inspection, your sampling requirements and the reports you need. We will confirm these details in your quotation.
From a clear requirement to a documented decision.
- 01
Create the requirement map
Assign each required behavior a test case, stimulus, expected response and acceptance limit. Mark requirements that are not tested in production.
- 02
Define and validate the setup
Agree fixtures, instruments, loads, firmware and software versions. Establish safe operating limits and validate the sequence with suitable reference conditions.
- 03
Run the controlled sequence
Identify the unit and configuration, execute the approved steps and stop safely when a condition requires it. Record measured outcomes rather than only an operator impression.
- 04
Review and release
Apply the agreed pass/fail logic, preserve diagnostic results and record authorized rework/retest. Release the final configuration only after required tests and exceptions are resolved.
A functional result should be reproducible.
Automated test frameworks can organize measurements, limits and result records. The project still needs an approved specification to determine what those tests mean. [S31]
- Unit and software identity
- Part/revision, serial or lot, firmware version, configuration and test-program revision.
- Test conditions
- Fixture and instrument identification, input/load conditions and relevant environmental settings.
- Requirement results
- Test-case identifier, stimulus, measured response, acceptance limits and pass/fail decision.
- Disposition history
- Failure details, approved correction, retest scope, final configuration and release status.
A power-on pass is not a reliability qualification.
A production functional test covers the behaviors and conditions actually exercised. It does not automatically demonstrate service life, environmental endurance, EMC performance or regulatory conformity. Order any required qualification or compliance work as a separate, clearly defined scope.
Functional Testing (FCT) FAQs
Find answers about inspection methods, reports and approvals before placing your order.
How does FCT differ from ICT?
ICT targets selected component and interconnect checks. FCT verifies specified operating responses of the powered assembly or system. Some capabilities overlap, but the approved requirements and sequence define the actual coverage. [S35] [S31]
Is turning on an LED a complete functional test?
Only when that is the entire agreed requirement, which is usually a much narrower claim than full product operation. List the interfaces, loads and operating modes that must also be verified.
Can a reference board replace the written specification?
A reference board can help validate or troubleshoot the setup, but its behavior alone should not define acceptance. Use documented limits and control the reference unit’s configuration and status.
What must be supplied for a custom test fixture?
Provide interface details, mechanical access, loads, power conditions, required measurements and safety constraints. Agree fixture ownership, maintenance and revision responsibilities before development.
Does successful programming prove the firmware works?
No. Programming and version verification establish configuration. Functional cases must still exercise the required behaviors with the approved firmware and hardware combination.
Can the same test be used after a software update?
Review changed behavior, communication, timing, limits and stored parameters. Update and validate the sequence as required, then retain the new test and firmware versions with each result.
Technical references
- [S30]NI — PCB Assembly Test Toolkit
- [S31]NI — PCB Assembly Test Toolkit overview
- [S35]Teradyne — TestStation Systems: In-Circuit & Functional Production Test Platform (PDF)
Explore the inspection and testing references below. Include the applicable standards, acceptance criteria and required records with your enquiry so we can confirm the inspection plan for your board.