encoder connection to dsp

shady mamdouh

please i have some questions about encoder and using it with DSP. I know that there is a type of encoder gives three signals (A, B, and Z) (quadruture )and this type can be used with the eZdsp 28335 but when i went to the motor company, i found only motors with a built-in type of encoder gives (T+ and T- signals) (as the seller said) dn't know this type and i dont know if thiis type can be used with the dsp or not and how can i use it

i will use it to measure the speed and initial postion of PMSM

over 11 years ago

0 Rick Duncan over 11 years ago

TI__Guru** 114905 points

Hi Shady,

Can you clarify?
Are you looking for a motor with a quadrature encoder that interfaces with the eZdsp 28355?
If you are trying to determine if the built in encoder works, can you provide more details? Motor model and encoder outputs will help.

Thanks.

0 shady mamdouh over 11 years ago in reply to Rick Duncan

Intellectual 575 points

Hi Rick,

I want to buy a motor (PMSM) with built in encoder and I knew that the encoder gives 3 signals A,B and Z (for quadrature type)
but the available in a near company for me is a motor with encoder gives serial communication signals called T+ and T- and I don't know if this type can be connected to the DSP (ezdsp f28335) or not
Thanks

0 Adam D. Reynolds over 11 years ago in reply to shady mamdouh

Guru 12800 points

Shady,

It sounds like your encoder communicates over a communication bus and not with incremental signals. This encoder could be either CAN or RS485 for the physical layer you described, but as for the application layer it could be a lot of different protocols.

It would be helpful if you can provide more information about your encoder. Without knowing the exact physical and application layers it would be impossible to say that the eZdsp can work with it.

0 shady mamdouh over 11 years ago in reply to Adam D. Reynolds

Intellectual 575 points

thanks for your reply adam
the motor which i found in the company is DELTA EMCA-c20604ES (which is series A2) also series B2 is available and the available datasheet is only for the motor
www.delta.com.tw/.../download_main.asp;pid=2&cid=1&tpid=1
i can't find a datasheet for the encoder

0 Adam D. Reynolds over 11 years ago in reply to shady mamdouh

Guru 12800 points

Shady,

I did a bit of research and it looks like they use a serial interface for the encoders. Most likely RS485. This should be readable by the eZdsp with the proper translation circuit.

You will need to figure out the application interface to allow your software to read this encoder.

0 shady mamdouh over 11 years ago in reply to Adam D. Reynolds

Intellectual 575 points

Dear Adam,

please give me more details for how to connect the ecoder with the dsp

0 Adam D. Reynolds over 11 years ago in reply to shady mamdouh

Guru 12800 points

Shady,

The encoder is RS485 which cannot be sent into the UART on the eZdsp. So you will need to convert the signal so that your eZdsp can read it.

You will most likely need a special IC in order to do this conversion. TI has a range of parts that are available to do this. I found this link which lists them: www.ti.com/rs485-ca.

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encoder connection to dsp