MSP430F67641A: Questions about calibration process

Hello Chandra,

In future posts, please use a title that summarizes your question, not just the part number (I've updated it for this thread). It would definitely help others in the community who may have the same question find your posts.

To answer your question, the gain calibration which includes (a) voltage and current (b) active power gets done at 0 degrees phase shift (PF = 1). Then, phase calibration is done at PF = 0.5. If you were to perform phase calibration before the active power gain calibration, the results may not be as accurate but more importantly, you'd need to change the PF from 1 to 0.5 back to 1 (3 changes) rather than from 1 to 0.5 (2 changes).

Although it doesn't support the MSP430F67641A devices, I did want to highlight our Energy Measurement Design Center (EMDC) for the MSP430F67xxA and MS430i20x1 devices. You can use a GUI to quickly and easily configure the MCU and sensors, generate the code, calibrate the system and view the results.

Accelerate your metering design with the new Energy Measurement Design Center and software library for MSP430™ MCUs

Regards,

James

Sir,

Thanks.

For about eight years ,I have been using 71M6533 from Teridian and the calibration software designed by us keeps the Voltage,Current Ib ,and PF at 0.5 ,and first calibrate voltage,then calibrate current and later do the phase angle correction.

Immediately at the same power source setting ,the energy accuracy through the pulses are done and always we got the precision with in 0.15%.

Recently the Emulator ADM51 accidentally got burnt due a new engineer putting on the unit and plugged in the emulator .

Now the device which we were using 71M6533 ,which was based of 8051 core appears to have been changed.

The company representatives are not supportive .

Also it is very confusing because we hear three names,Teridian,Maxim,and Silergy.

Hence I was planning to switch to Texas.I have been using TI micro for decades.

Texas generally answers quickly and solutions gets arrived at.

Also as I understand Texas MSP 430 core has vastly improved in many  ways(while I am not an expert,I think TI listens to customers and improves) and emulators are cost effective.

Hence I am seeking support from Ti.

Hence my question.

Any way ,will go through the documents that has been cited ,while I await the response.

Regards

VTC

Part Number: MSP430F67641A

Sir,

Can we get the compute engine software to compute RMS Voltage, RMS current ,real power(watts), calibration constant locations and the corrections, as a module,so that we can write the remaining part of the system software by ourselves.

We don't want to buy any EVM board and hence can not use GUI.

Hence a separate compute engine will help us to complete the product development..

Regards

VTC