Communication betw. 429 and multiple stepper-motor-drivers

[cschwab]

Subject: Communication between TMC429 and multiple stepper-motor-drivers TMC26x


Hello,

I have a question concerning the communication between a TMC429 and, for example, 3 TMC26x-drivers.
On the datasheet of the TMC429 (http://www.trinamic.com/tmc/media/Downl ... asheet.pdf), figure 3-4 on page 5, there is a connection between SDO of the third TMC26x with the SDI_S of the TMC429. The SDO's of the other TMC26x's are not connected. How can these TMC26x's communicate with the TMC429?

Kind regards

[Dr.LarsLarsson (TRINAMIC)]

Without connected SDO of the drivers the TMC429 cannot read back diagnosis information. That figure was intended for SPI drivers that do not have an SDO. Drivers without SDO cannot be chained but the TMC429 can also address up to three of those kind of drivers with its individual chip select signals.