Reading Info from smoothieboard serial interface

Hi Arthur,
How can I read the info about temperature/speed/ and files on the Sd-card from the Tx/Rx pins on Smoothieboard?
The Sd-card can be the one connected to the SPI port? or it has to be only the one on the board?
Is that possible?
If yes, can you please tell me which command I need to use?
Thank you for your time
Regards

Imported from wikidot

Hi Arthur, why do you respond to simple questions and not to those where your support is needed?