Hello, friends welcome to another interesting post. In this post, we will discuss the fundamental concepts of automated testing. Automated testing comprises of software elements that operate and do execution of the testing operation and hardware elements which implement testing coding and link the unit under testing.
In this post, we will define the elements of basic automated testing systems and some other factors of automated testing so let’s get started with Fundamental Concepts of Automated Testing.
Basic Automated Test System
- The below figure indicates the elements which create the basic automated testing network.
- The test controller implements test coding which runs the test system. The test controller is a PC running proprietary company code workstation running commercial testing software and can be a dedicated element of the commercial automated testing network.
- The testing controller does communication with the testing devices testing instruments and testing results over system buses.
- The type of these buses can be proprietary or adhere to industrial measurements. The testing devices testing instruments and testing results uses a similar or different category of buses for communication with the testing controller.
- The testing devices and testing instruments offer power and testing signals to the unit under testing and calculating the operation features of the module over the testing.
- The testing fixtures interlinks to the automated testing network to the UUT or unit under test.
- The test controller link to the switching control that in turn regulates the switching circuitry.
- The switching circuitry interlinks the testing devices and testing modules to certain positions known as the testing point at the module over which the test is done.
- The UUT can be one element, circuitry board or hole electronics packaging. Different manufacturing companies sometimes do standardization interfacing among the testing fixture and UUT.
- Engineers should make sure that their complete module designing to follow these measures.
- A different circuitry are more complicated manufacturers like as the joint test association group JTAG has developed and created industrial measure therefore companies can create and use standardized testing device and processes.
Fixtures of Test
- The figure is shown in the below figure test controller interlink to the switching control.
- The switching control defines instructions from the test controller to manage the switching circuits that interlinks the testing device and test instrument with the certain testing points at the UUT.
- The below figure indicates an example of switching circuitry which uses relays.
- The circuit shown in the above figure comprises of thirty-two relays for interlink 4 two terminals ports with the 4 TP terminals.
- The switching controller provides voltage to the coil points of one of the really to close the connections for that specif really.
- This interlinks the test device or modules lead through a port terminal to one of the testing points at the unit under testing from the testing terminal.
- The switching circuitry in the above figure needed thirty-two relays for interlinking any of 8 port connections to any testing point.
- Some testing network has hundreds of testing points and can need numerous layers.
- Interlinking the certain port terminal to a certain testing point decreases the price and complication of the testing network but it also decreases its reliability.
Measurement of Current
- The results showed in the above figure interlinked devices and instruments at the 2 terminal ports in parallel combination to the circuit linked about the sets fo testing point.
- It operates well for voltage and resistance calculations but not for the measurement of current.
- There are many processes for the testing network to find current.
- We can use a power supply that can find the value of the current. It works fine if the calculation are good for the application of test.
- Finds the voltage about the resistance in series combination to the element of interest and apply ohm law to find the current. the disadvantage is that the manufacturer should add a sense of resistance for testing if the circuitry does not have.
- COnnect extra switching circuits for supporting current calculations at the port and testing point connections. It will increase the complication of the testing network.
- connect an exterior sense resistance and voltmeter at one terminal of every 2 terminal port can be seen in below figure.
- This raises the cost of the testing system. Limited current calculations at one port can decrease this but it will decrease the flexibility of the network.
- The second drawback is that the testing network should do compensation for the voltage loss about the resistance to provide the accurate voltage at the unit over which the test is performing.
Sample Automated Test System
- The below figure indicates an example of an automated testing system based on the switching circuitry discussed in the above figure.
- We can see that system links the dc power supply with the terminal of port first and DMM with he terminals of port two and three.
- The UUT comprises of one-kilo resistance and 1N009 diode in series combination.
- The automated testing system do verification of that either diode is operating well through the forward biasing the diode and calculating the diode voltage and current.
- To perform this test controller in automated testing do these operations.
- Adjust the dc supply at five volts dc.
- Set first DDM and second DMM fo dc voltemnet operation.
- Links the positive and negative points of dc supply to testing point terminals TP1 and TP3.
- Links the positive and negative terminals of first DMM to testing point TPI and TP2.
- Links the positive and negative terminals of second digital multimeter with the testing point terminals TP2 and TP3.
- DO activation of dc supply outputs.
- Finds the resistance voltage at first DMM
- find diode voltage value at the second DMM.
That is a detailed post about Fundamental Concepts of Automated Testing if you have any further query ask in comments. Thanks for reading. have a nice day.