Hello Dear All,
I am trying to implement AD2S1210 resolver digital converter chip to motor position reading with using TI 28379 DSP. I have developed control board for AD2S1210 circuit, and I am getting position data with SPI communication it works perfect. I have not changed configuration register and only I am configuring RES0 and RES1 in reading moode either 12 or 16 bit resolution, it works.
However, in my application I want to use also encoder (A, B, NM) signal to DSP and I want to read position data in parallel to SPI interface. I did not changed to configuration register, I just set RES0 and RES1 to 16 bit resolution in reading mode. I have flowing problems:
- In stationary resolver position(there is no movement in rotor), A and B signals has variable frequency pulse, after some time it goes fixed period signals close to 10 MhZ, it is like oscillator signal.
- In constant speed resolver mode ( rotor in constant speed mode), A and B signal has not regular frequency signal, A and B has non-uniform periodic signal.
Instead of using my inverter control board which includes AD2s1210 chip, I tried my DSP codes with my DSP, I have integrated my DSP to AD2S1210 Evaluation Board . My code works perfect both SPI and encoder works great. In encoder signals A and B have
- constant signal at stationary rotor position.
- uniform frequency at constant speed of rotor.
as it is expected.
Please, could you help me to find out the root cause of the problem. Is it in my inverter control board regarding to ad2s1210 circuitry peripheral, misconnection, or oscillator signal?
Or is the problem related to configuration, I am missing something
My initial response was going to be that you need to ensure that the ENRES0 and ENRES1 bits for the encoder resolution are set appropriately to be less than or equal to the resolution of the setting in RES0/RES1. However, if things are working in the Evaluation Board setup then I'm confused.
Could you please send the following.
1) A schematic of your inverter control board with the AD2S1210 specific connectivity.
2) A capture of the digital configuration showing the data you are writing to the part, including a verification of the data (Read contents of memory).
3) Indication of any faults in the system.
4) Scope Capture of input signals to the device in your inverter.
I have one issue left, I have configured configuration register both RES and EnRES 12 bit successfully, after that I am trying to read data from quadrature signals also SPI in parallel. Quadrature position reading works fine. However, I can not read SPI data after configuration for resolution. After configuration I switch reading mode using A0 and A1 pins.When I was using default resolutions mode I was reading data from SPI and quadrature signals simultaneously, it was working fine.Do you have any idea to solve this problem?Thank you for your support.
What are the settings of A0 and A1 when you go back to read position?
Also have you tied the external RES0 and RES1 pins to match the control register? (pins 1 and 48)? These must match for proper operation.
I have solved the problem, it was related to my code. Thank you for your support.