The PCB Functional Test Fixture Machine is the gate-keeper that allows only fully working boards to be shipped out of an assembly line. The tester looks at the whole PCB and not at individual components. It simulates the functions of the boards and compares it to the expected operation of the board as per the design with allowance for minor design variations. PCB Functional Test Fixture Machine typically interfaces to the PCB under test via its edge connector or a test-probe point.