Automated systems are produced by using the built-in capability of the instruments to run test programs and output the data results as shown below. Often, the switching function is included within the sourcing or measuring instrument, such as an oscilloscope.
Measure Instrument Limited Control
As the automatic test system size increases, or as test requirements become more complex, a computer is added to run a test program and execute tests. Advantages to automatic test systems include:
Testing permits operator interaction. The operator can base current test parameters on previous test results.
Known system problems are corrected.
Because operator intervention is less, there are fewer chances for test errors.
Test results are more effectively analyzed since they are compiled into a database. Complex calculations are possible.
Throughput of units under test is higher.
When automating the test system, switching functions must also be automated. In systems where the signals are electrical, a programmable instrument called a scanner, matrix, programmable switch, multiplexer, or switching network is employed.