My devkit was working fine with both wifi and ethernet. But now while connecting the MFAM with Magview using ethernet port I am getting the error "Error 56 occurred at TCP Open Connection in MagViewMFAM_V1_1_3_2.vi". Please see the screenshot attached. I am not getting any data plotted. It is working well with wifi. I put the right software in the SD card and it is getting installed. The ethernet port setting is also fine according to Appendix A of the user manual. Any help to resolve this error would be appreciated. Thanks in advanced.

1. The compass inside the MFAM driver box is NOT a top-rated vector magnetometer, in terms of reading accuracy and axis orthogonality. A top-rated vector magnetometer, capable of producing good vector sum readings, costs thousands of dollars and is much bigger in size.

2. The compass is integrated on the MFAM driver board, which has many magnetic components. The magnetic field at the compass location is altered by these magnetic components.

Although the compass doesn't generate good absolute readings, its relative angle measurement (related to the reading repeatability) is good enough to be used for maneuver noise (heading effect) compensation.

Thanks

I need MFAM live data streaming from ethernet or serial UART5 for my project. Initially, I am planning to write a piece of code using C++ that reads the data from one of the ports and prints it on the terminal. To be sure that data is present on UART5, I connected this port to the USB port of my laptop using a suitable cable and tried to monitor data using Putty with different baud rates but found nothing. Is data streaming available on UART5 by default? or do I need to enable it?

I can see data on the ethernet port using MagView. Ethernet port uses TCP protocol. Is there any way to enable UDP on the ethernet port? In case I write code to read the ethernet port using TCP then please suggest a suitable reference to start.

Thanks a lot

It is not obvious that 60 or 50 hertz electromagnetic radiation is real, since in ordinary experience any power line “noise” is electrostatically coupled into a system (think 60 hertz hum on a stereo system) and is a fault that needs to be fixed. In this case however the variation in the magnetic field is induced by the power grid and is real. The magnetometer is simply and dutifully reporting the variation.

These power line variations are to some extent present everywhere – even miles from the nearest power line. But obviously being close to power lines will increase the amplitude of the variations a lot. Often on a MagArrow survey the power line variations will be larger at one end of the survey area than the other. Poking in the GPS coordinates at the survey area nearest the larger variations into Google Earth will usually reveal the power lines from an aerial view – even if they are not visible on the ground.

After applying a Fourier Frequency Transform on the MFAM data to identify the noise sources, 50 and 60 Hz noise amplitudes are easily observed. Also observable is the likely to be 20.8 Hz Schumann resonance of the third node and some other ultra-low frequency electro magnetic radiation produced naturally by the Earth. Harmonics of 60 Hz are also present.

Another common question is “Why is the power line variations not a sine wave like the power line voltage?” Remember that voltages do not make magnetic fields. Only current generates magnetic fields, and the current being drawn is not a sine wave at all. Many loads, for example, only draw current at the voltage peaks. This makes for a non-sinusoidal magnetic field that is rich in harmonics. Also note that most power distribution system use a 3 phase topology. The ripple current in such a system will be 150 or 180 Hz. Thus you will often see large peaks in the power spectrum at these frequencies and their harmonics.

To make sure that the parts are magnetically clean, you can set up the MFAM Dev Kit in the gradiometer mode.

1. Have the two sensors separated by 20cm or more.

2. Turn on the gradient reading (green curve) in MagViewMFAM.

3. Place the part 10cm to one sensor and 30cm to the other.

4. Rotate the part while monitoring the gradient curve. Make sure you don't have any magnetic parts (such as keys, cell phone, watch) with you while doing this.

5. The peak-to-peak difference in the gradient curve (you may have to adjust the gradient scale if the curve wraps on screen) is the magnetic signature of the part at 10cm.

6. For the magnetic signature at different distances, scale the reading as 1/R^3. For example, if the part will be 20cm away, its magnetic signature should be 1/8 of of the reading at 10cm.