PCB Blog - What is functional testing(FCT)?

1. Basic Introduction to FCT

The FCT (Functional Circuit Test) circuit board dynamic function tester takes the tested unit on the circuit board as a functional unit, provides input signals to it, and detects signals according to the design requirements of the functional unit. Improve the automation level of testing with advanced and flexible solutions. And it greatly shortens the fault finding time, making it the best method for quick repair and fault finding. This device is controlled by an industrial computer as the core, integrating a standard GPIB interface, multi-channel programmable waveform generator, programmable I/O channels, and data acquisition module. It can maximize the data acquisition and testing of various analog/digital signals of the circuit to be tested by users, and conduct qualitative or quantitative analysis through system software. In addition, through the GBIB interface, any device that meets the GPIB interface standard can also be connected to the system, providing unlimited expandable space in terms of functionality. In addition, the flexible and simple human-machine dialogue interface greatly facilitates user use.

2. The types of FCT test are divided into

2.1 According to the control mode:

It can be divided into manual control function testing, semi-automatic control function testing, and fully automatic control function testing

2.2 Based on controller type

It can be divided into MCU control mode, CPU control mode, PC control mode, PLC control mode, etc

3. The common benefits of using FCT test are

The advantage of using functional testing fixtures is that if they are the same product, even if the workers do not have very skilled technology, they can quickly use the fixture to produce a large number of good products with fewer defects and low variability. However, for diverse and limited production modes, the result of many fixtures actually leads to an increase in production costs.

4. The functional testing of PCBA is generally divided into the following parts:

4.1 System Control Center:

This part is generally composed of small or medium-sized central processing units such as PC, MCU, ARM, etc. Its main function is to control the entire testing process, judge and record the testing content of each step, and ultimately obtain the test results. It is the core brain of the entire testing system.

4.2 Control execution part:

The control execution part is mainly composed of I/O components, which are the sensing and executing mechanisms for testing process logic actions. The system uses it to build various testing environments and achieve testing functions.

4.3 Parameter measurement section:

The measurement part mainly consists of some measuring boards and instruments. It can mainly complete the collection of various analog or digital quantities during the testing process. So sometimes we refer to it as the data collection section.

4.4 Data processing and output section:

The purpose of our entire testing is each step and the final test result. How to store and output these results and data, making it more convenient for us to effectively control the quality of PCBA products, is the responsibility of the data processing and output section.