L6470 or L6480 X-Y simultaneous move

[jean-louis]

Posted on April 05, 2013 at 19:52

What is the best way to move 2 axis with such controler in a same time?

Shall I use SYNC output?

#l6470-l6480-xy

[Enrico Poli]

Posted on April 12, 2013 at 11:40

Hi,

I think the best way is to use the daisy chain feature.

If you connect your X and Y drivers in the same chain you are able to synchronize the command execution through the CS line.

Example:

You need to Move the X motor (1st of the chain) of 1024 usteps forward and stop the Y motor (2nd of the chain) at the same time.

You can do it using this sequence:

1. Force CS low
2. Send the NOP|MOVE(FW,...) bytes (the 1st byte transmitted is received by the Y motor and the second one is received by the X motor).
3. Rise CS
4. Force CS low
5. Send the NOP|NSTEP[byte2]
6. Rise CS
7. Force CS low
8. Send the NOP|NSTEP[byte1]
9. Rise CS
10. Force CS low
11. Send the SoftStop|NSTEP[byte0]
12. Rise CS --> X motor executes the SoftStop and Y motor executes the Move

[jean-louis]

Posted on April 16, 2013 at 22:21

Thanks for answering.

Ok for the daisy chain mode.

Ok for starting in the same time a ''move'' command.

How to have a synchronous move?

I have 2 motors X and Y.

For instance, I want to move 144 steps for X and 91 step for Y.

I want to start AND stop at the same time: I want to move on a straight line.

What-is the use of the sync pin ? would this pin usefull for XY move?

[Enrico Poli]

Posted on April 23, 2013 at 16:17

OK, I misunderstood your question.

In this case the control is more complex and requires some effort from the MCU side.

Maybe you can use a sequence of RUN commands performing the X-Y interpolation and checking the positioning through the ABS_POS registers.

Another solution is to use the step-clock mode, but in this case the BEMF compensation algorithm is disabled.

The synch output is designed to synchronize external events with the motor position (e.g. the MCU monitor the synch output through a counter).