HIPPY, A Software Development Project for the GW INSTEK GPT-9803 Hi-Potter Instrument

This was a short and fun project where I again employed Microsoft C#, this one to control an instrument and to record and graph the data from the instrument. 

Following the demise of Enclosures Engineering, Thomas Nguyen hired on at Vivid Inc (http://www.vividinc.com/) in Santa Clara. Thomas had become one of the top guys at Vivid, supervising much of the coating and painting work and engineering new capabilities for Vivid. He contacted me about a software development project involving the GW INSTEK GPT-9803 Hi-Potter instrument. Vivid was using the Hi-Potter instrument for testing the coatings that they produce, testing the coatings to determine the insulation quality of the coatings to hold off high voltages. They wanted to better automate their use of the instrument and record the data for presentation to the customers and also for advertising purposes. Vivid provides "a wide variety of surface coating applications" for "EMI/RFI shielding" and other purposes. This sounded like an interesting instrument control project and I was happy to again work with Thomas on the project.

BTW, the name HIPPY came about as a result of a typo in the email messages between Thomas and myself. I blamed Thomas for the typo but he denies any knowledge of the error but anyhow, HIPPY became as the name of the project.

INSTEK's GPT-9803 is quite a complex instrument, capable of a wide range of AC and DC testing that Vivid wanted to use to test their coatings. For details of the instrument, see: (http://www.gwinstek.com/en/product/productdetail.aspx?pid=39&mid=82&id=1315)

The GW INSTEK GPT-9803 Hi-Potter Instrument.

First I checked with National Instruments to see if software was already available using LabView (http://www.ni.com/labview/) but found nothing available at the time. LabView seemed to be the obvious choice for the instrument control application but not being a LabView expert, I looked for other possible software packages or tools that I could use to develop an application for Vivid. I am able to develop LabWindows/CVI (http://www.ni.com/lwcvi/) code and applications and I really like the product, having used it at LLNL for the Smart Sampler project that I posted about back in October. However, I didn't have a license to use LW/CVI but I was familiar with Microsoft C# (http://msdn.microsoft.com/en-us/library/kx37x362.aspx) as I had recently used C# for the Phase 3 Paint Flow Control Project. So I selected it for the Hi-Potter project as it appeared to provide the necessary tools for the job, providing means for producing a GUI and the C code to communicate with and control the Hi-Potter and means to acquired data from the GPT-9803.

The GPT-9803 is a multimode instrument, capable of outputting AC and DC voltages in Steady-State or Ramp mode at variable speeds and at variable maximum voltages. For the AC voltages, the frequency can be selected to be 50 or 60 Hz. The maximum AC voltage is 5 kV and the max DC voltage is 6 kV. The commands are too complex to list, so it's better to show the C# GUI screen that I produced to control the instrument.

In the screenshot below, the User can select AC, DC, IR or GB mode. The IR mode is an Insulation Resistance test and the GB mode is a Ground Bond, or a test of the grounding in a device or instrument. More descriptions of various Hi-Potter tests are in the Wikipedia article: http://en.wikipedia.org/wiki/Electrical_safety_testing.

GPT-9803 RAMP Test Screen.

I programmed the GPT-9803 for its many modes. For the Ramp modes, I provided means for setting the max AC or DC voltages, the step rate, the max current etc. Although generally, the GPT-9803 is used in Ramp modes, I also I made commands and the means to operate the GPT-9803 in the IR and GB modes. The GUI shows the results for testing of an aluminum plate sample that was coated on one side with an insulating material and sandwiched with another aluminum plate for connection to the GPT-9803 for insulation testing. The graphs show the applied voltage ramping up to the max value and the current leaking through the sample. For the test, the maximum current was set at 2 mA and the current graph shows the current ramping up to 2 mA. The Ramp was halted by the GPT-9803 when the max current was reached during the test. For this test the voltage reached a little over 1.2 kV before the current limit was reached. The Hi-Potter code recorded the ramping voltage and current in a log file for reporting to the customer.

Below the Mode select buttons is a description of the commands for the individual modes. A larger view is below, showing just the possible commands for DC voltage tests.

Command Descriptions for the DC tests.

Below are the Utility Commands:

Although it looks complex to operate the software, it actually is quite simple. Roughly, the steps are:

1. Select the Mode: DC, AC, IR or GB by clicking on the radio button.
2. Click on one of the Commands, for example, the "Sets or Returns the DCW VOLTAGE in kV ..."
3.  If, for example, the DCW VOLTAGE command is selected, a scroll bar will show up on the screen to allow the operator to select the voltage and the selected voltage will be displayed in the Manual Command Text box.
4. Select the maximum current current allowed, the DCW HI-SET CURRENT VALUE in mA ...
5. The user/operator can select the Data Acq(uisition) mode and the Data Acquisition timing, then click Start Data Acquisition and then click Start Ramp. 
6. During the test, the data are graphed and stored in a Log file.
7. When the command times out or if a limit is reached, the test will stop and the Log file will be closed.

The results of the test are graphed and also the data are stored in a Log file for entering into a report.

Happily the software works well to control the GPT-9803, acquiring test data that is provided to Vivid's customer and also the software can be used for advertising purposes to demonstrate Vivid's capabilities.

This was a rather straightforward project, completed rapidly and relatively easy by the capability of the GW INSTEK GPT-9803 Hi-Potter instrument and the use of Microsoft C#.