AD2S1210 EVAL Board with SDP CB1Z: square wave position output

Hyacinth,

Couple of things to check

1) Make sure the RES1, RES0 settings on the evaluation board match your software setting in the control register of 10bits and vice versa.

2) Let me know what resolver your using so I can check the wiring diagram against the connectivity on the RDC.   One thing to try quickly is reversing the polarity of your excitation connectivity to see if that helps the loop lock. This will account for the 180 degree phase shift coming from the inverting gain.   I'm not sure this is it but it is worth a try.

3) It's interesting that you are getting a DOS MISMATCH fault, at least in the screen cap you sent.   That might indicate that something is off with the wiring in the front-end but I think that's unlikely.

Let's see how you fair with the first two suggestions and let me know if anything changes with regards to the fault....Try reading/clearing the fault register a couple of times to see if you can get those fault LEDS to go out.   If so we are probably getting close.

The next step I'll have you do is take me through your jumper connections so I can check them against the defaults.

Sean

Hyacinth,

I did a little digging and the TAMAGAWA-SEIKI color pattern I found would seem to suggest the following.

Please note there are two types +type and -type so you may need to swap Yellow and Blue to get the correct quadrant of operation.  Is it possible you have the resolver miswired or is your wiring diagram different then this?

Sean

Hi Sean,

Thanks a lot for your help!!!

Here is the feedback regarding your suggestions:

(1) RS0 RS1 are in position C which means the resolution is controlled via J2. So it is only controlled by software, right? Position A and B are controlled by Vdrive and Dgnd, which is not my case.

(2) You are absolutely right about the wiring issue. I swapped the cosine and sine wiring at first. Then I tried your suggestion, both blue(s4)-yellow(s2) and blue(s2)-yellow(s4). However, the position output is still square waves.

(3) There are more faults than the DOS mismatch but only the DOS mismatch was captured by the screenshot. Sin/cos inputs clipped, tacking error, phase error were all witnessed when I did the test. I checked the wiring and make sure the connection is firm. So got no idea what caused the fault.

This morning the fault detection configuration was left as the original ones, no error occurred this time (but still square positions). I have to doubt if it is my fault detection configuration that leads to the fault report. The orange light on the SDP board is on after I set up the fault detection part via software. Then I clear the fault many times as you suggested, the orange light then is off but the DOS mismatch error occurred again. Then I click "read" the DOS mismatch is flashing.  

(4) All the jumpers are the default ones.

• Power supplies are in position A that is the onboard regulator and finally by the 9V charger.
• The excitation driver is in position A which is the AD8662 amp.
• Excitation driver gain is in B which is 1.54.
• Configuration pins are in position C. 
• Digital interface options are in positions C(LK2 and LK2) and B (L1), which haven't been tested by me.

So I got stuck again. Please indicate to me if you have any idea. Thanks again for your time and kindness!!!

Best,

Kun

You are right. I got some problem with the resolver at first cuz I don't have the type number or the series number. 

The Tamagawa resolver I got is a variable reluctance resolver. There are white-green-blue-yellow-red-black wires. The rotor has 4 poles. Based on this I found a brochure from the Tamagawa website.

 It is a Singlsyn series lead type resolver. It should be the S21 series because I measure the diameter. 

But the line colors are different from the brochure. I measured the connectivity and impedance of the six lines and decide the pairs, which are the same as you found.  The transformation ratio should be 0.286+/-10%, which is around 3.5/11. But the impedance does not match the measured ones. For the excitation winding, what I measured from the multimeter is around 30 ohms. The sine and cosine winding is around 60 ohms. They are way lower than the nominated values (120, 436, 436, respectively). Can you please share what you found for the resolver? Seems I dug into the wrong hole. 

Thanks!!!

Best,

Kun

Hyacinth said:

RS0 RS1 are in position C which means the resolution is controlled via J2. So it is only controlled by software, right? Position A and B are controlled by Vdrive and Dgnd, which is not my case.

Let me get back to you on this but yes it should work that way.   To be honest I've done most of my testing with this part in 12-bit mode so I just want to make sure the evaluation software takes care of this automatically when you update the control word. 

Hyacinth said:

(2) You are absolutely right about the wiring issue. I swapped the cosine and sine wiring at first. Then I tried your suggestion, both blue(s4)-yellow(s2) and blue(s2)-yellow(s4). However, the position output is still square waves.

So how do you currently have the wiring connected?  Is it per the wiring table I provided last evening?

Hyacinth said:

(3) There are more faults than the DOS mismatch but only the DOS mismatch was captured by the screenshot. Sin/cos inputs clipped, tacking error, phase error were all witnessed when I did the test. I checked the wiring and make sure the connection is firm. So got no idea what caused the fault.

It is possible that on startup the device may indicate false faults which is why after RESET the first thing you should do is execute a FAULT register clear.  The fact that you are getting a DOS mismatch fault indicates that you have an imbalance in the SIN/COS voltages relative to what is preset by default.  Can you confirm that this fault light is only set after rotating the resolver.   That is with a static position it doesn't light correct?

To be honest I'm starting to wonder if because of the miswiring if you didn't damage the RDC (not sure how) and if  on of the inputs isn't damaged.  What doesn't make sense is why you wouldn't get an LOS fault if a signal was completely missing so something is definitely not right..  Do you have another board you can try with the wiring connected correctly to see if you can't make it work?   If not you may want to contact your local ADI sales representative or distribution representative to see if you can get another one.   I've actually recently seen this type of behavior in our lab with a board only it turned out that it was our resolver simulator that was not outputting the AM sin wave and depending on the amplitude of the working channel the output would flip from 0 to 90.

I would also recommend contacting Tamagawa directly to get a wiring diagram you can rely on based on the part number.  

Let me know how things go.  We'll get to the bottom of this shortly and I will be back to confirm 100% the software driver works as it should once I've confirmed.

Sean

Hyacinth,

I verified that the software does correctly configure the RES0, RES1 pins so you are fine there.

Sean

Hi Sean,

Thanks for your help!

For the wiring, I am pretty sure that exc-exc/, sin+-sin-, cos+-cos- are the pairs you showed me (I tested the conductivity and impedance of the six lines.) Right now I am using the wiring style you shared with me. I think I need to confirm withTamagawa company.  

I haven't met the LOS error so far. And I only have one ADI board at hand. I will test the board tomorrow and let you know under what cases the error occurres.

You mentioned that you encountered the problem before:

@skowalik said:

I've actually recently seen this type of behavior in our lab with a board only it turned out that it was our resolver simulator that was not outputting the AM sin wave and depending on the amplitude of the working channel the output would flip from 0 to 90.

May I know what is the AM sin wave? Right now I am quite suspious about the amplitude of the sine and cos waves. I think the amplitude is not high enough and the wave quality is bad. May I know the waveform amplitude on your board? Maybe the board is working properly but the input signals have some issues.

Regards,

Kun

Here is my feedback:

Power on and not rotate the shaft.

• The ADI board reports DOS and LOT errors.
• The SDP board only has one green power light which is normal.

Then spin the shaft to change the position.

• Still the DOS and LOT errors on ADI board
• Still only green power light on SDP board

Start the software.=> Both DOS LOT lights off => read data under the default setting=> DOS LOT lights on again & on the software there is 'Tracking error' => clear the error many times => the DOS LOT lights flashing on the board, then off. The tracking error is cleared on the software panel too.

Change the register configuration via software

• set 10kHz => DOS LOT lights on & Orange status of the SDP board on
• set 44degree, enable hysteresis, 14bits, 14bits => Only DOS light on & on the software, Sin/cos mismatch and tracking error occurred 
• Do nothing to the fault register

Read data again. The position is shown below. Observations when rotating the rotor or keeping it still are: DOS is on, LOT is flashing on the board; tracking error, sine/cosine mismatch, sine/cosine over range are flashing on the software. 

Then clear the fault via software and set up the fault detection register.

After setting up the fault register, the fault errors on the software are cleared. However the DOS light is still on. 

Read data again.The position is shown below.On the software, the Sine/cosine mismatch and over range error are flashing (not always on) but the DOS light is always on of the board. When the rotor stops rotating, the DOS errors on the software stop flashing so you can see them in the picture below. DOS light is still on.

Then I changed the configuration and tries again. What I observed above is still there. 

Then I restart the power and redo the process. The DOS light is on again. 

So the question is: Why the DOS light is always on? It cannot be removed via software. 

Can you spot any clues from my operations?

Thanks as always for your help!

Hi Sean,

Thanks for your help!

I already get the wiring for the resolver but the resolver output signal is still square waves. 

You mentioned that you encountered the problem before:

@skowalik said:

I've actually recently seen this type of behavior in our lab with a board only it turned out that it was our resolver simulator that was not outputting the AM sin wave and depending on the amplitude of the working channel the output would flip from 0 to 90.

May I know what is the AM sin wave? If it has something to do with the resolver, I will purchase a new resolver. Right now I am quite suspicious about the amplitude of the sine and cos waves. Maybe the board is working properly but the input signals have some issues.

I am looking forward to your answer. Thanks!!!

Kun

Hyacinth,

Apologies for the delay in my response but I was on vacation over the last week.  

In my case the amplitude of my sine channel in the fault case was always 0V differential as the simulator channel was damaged. 

For the AD2S1210 to work properly the differential amplitude (peak-to-peak) will need to be between 2.3Vpp and 4.1Vpp as specified in the datasheet.   If we assume each of the outputs from the resolver generates a balanced sinusoidal signal such that 1/2 the peak value is applied to each output leg in anti-phase then that means each input (SIN, SINLO, COS, COSLO) would see 2.0Vpp maximum and sit on top of a common mode voltage of 1.25V generated by the device or similar or greater potential generated by the input signal conditioning.  Failure to generate sufficient amplitude, assuming the default configuration,  will result in the generation of LOS, too much amplitude will result in DOS or if there is insufficient common mode for a given amplitude you may clip one of the input clipping thresholds.    

I would also check the device performance in 12-bit mode to see if you can't get the correct output.   This would at least verify if the RDC core is working correctly.

Let me know how this works out.

Sean