Week 17 : Solving the Timeout Error

 We check our coding and we quickly realize that the VI in the red box is causing the timeout error. The function of this VI is to configure current range for a specific test. This is part of the forever loop for power meter in which it keeps on acquiring the V,A,W readings at high speed. After it finishes 1 iteration, it will configure the current range again until the program stop. Hence, we put this VI outside the forever loop so that it only run once.



As we thought the problem has been resolved, this is what we get when we execute the program, an unknown error. Despite this error, our program has made some improvement over the timeout error. The program don't crash that often, sometimes it executes without crashing in the whole test which is around 4 minutes. We are close to solve this error.

Week 16 : A New Problem Emerged

 In order to increase the speed of our program, we introduce a Run (Waveform) button in the oscilloscope program. Our program will only capture the waveform and autosets it to the best voltage vs time when the button is pressed.

The same modification goes to Agilent Technologies 34980A. This is because when all the instruments run together at the same time, the program will become very slow. This will jeopardize the whole test as the readings from the power meter will not be real time, it will update once almost every 8 seconds which is unacceptable.The power meter is crucial for both Open Circuit and Short Circuit tests, the 3 phase voltages has to be set within the range states in ATP. If the voltages are too much out of range, it will cause the ATU/GATU to overheat and thus damage the units.

 

Upon successfully communicate with the power supply and acquire data at real time for power meter, a new problem emerged which is shown as above.This is a timeout error when the instruments may not respond rapidly to commands written to the port, causing a large delay between VISA Write and VISA Read. This means that our program crashes when it is half way executed, when it crashes it will stop communicating with all the instruments that are using GPIB-USB cable.

Hence a Wait function between VISA Write and Read to effectively avoid a potential timeout error.

 

We add in the wait function for the power supply as well as power meter, however the program still crash. We suspect the power meter is causing the error because it is always the first one to crash.. Furthermore the test bench is occupied so we are unable to carry out investigation of the problem. We hope to resolve this by next week.