Wan't to know how to test for trapezoidal wave in TMC9660 using osclloscope

What did you try and what did you observe ? You need to be more specific.

Was the motor power turned on when you initially reported that the error LED was lit when using PARAM mode ?

If not, does turning the motor power on change the state of the error LED ?

Do you get a VM voltage reading displayed in the TMCL-IDE ?

If not did you check if VM was present on the landungsbruecke board ?

Looks like it appears on pin 1 of the interface connector

and passes through a voltage divider before being presented to the ADC of the interface microcontroller 

The Wizard Pool should make it easier, otherwise you will need to configure the params/registers manually.

It's probably not showing though as it looks like you have skipped over the bootloader configuration stage in the user guide.

Tried it, still not working. Need someway to set Wizard Pool of the software.

Looks like 'VM is not available' is one of the error conditions that would cause it to light.

Another reference to checking the power supply if the error LED glows: 

Fault LED was off.

I have raised issue to ADI engineering zone.

That may be expected behaviour until you manually configure the appropriate parameters and apply power to the motor.

Was the fault LED also lit on the TMC9660-3PH-EVAL board ? If so it may be passing the error condition from the TMC9660 device.

Perhaps take a look at the default configuration states after power on/reset and set the parameters appropriately for your use case.

https://www.analog.com/media/en/technical-documentation/data-sheets/tmc9660-parameter-mode-reference-manual.pdf

Showing error in microcontroller board when board configuration set to TMC-9660-3PH(PRAM)

Ow, just remembered that the road test is for a brushless DC motor ...

jc2048 said:

You aren't going to see a trapezoidal waveform, whatever you do, because it's a velocity profile you're looking at in the diagram, not a voltage waveform (as Doug helpfully pointed out)

Yes, This is a capture of a trapezoidal I did for a stepper motor project,

Velocity profile is visible because the frequency at the begin ramps up, then stable in the middle, then ramps down.

I've just returned from walking to the shops to buy some groceries. On the way I realised that, of course, it only takes two half-bridges to make a full bridge so, with three outputs, at any instant one will be undriven and after settling will presumably end up at the half level (the motor Y configuration connecting it to the midpoint of two equal inductors connected between the rails), so suggesting 12V for the trigger level wasn't very inspired. Go higher or lower.

So, if I'm now understanding it correctly, the PWM is there to control the current, so it can adapt to different motors and circumstances, not the velocity which comes from the rate of sequencing round the phases.

Sorry for any confusion - I did say I didn't know a lot about motors and their controllers.