Trinamic Discussion Groups

[mimo]

Hi,

We are using the TMCM-610 module via USB interface.

When we tested the TMCL IDE StallGuard functions, the Profiler program runs very unstable:
When I start the Profiler, the program accelerates the motor about 2 seconds and then crash (graphical output stops, motor acceleration stops, motor velocity keeps constant).
After about 5 seconds the error message "The Connection to the module hase been lost!" pops up.

Is this a known bug of the StallGuard Profiler or a problem in combination with the USB interface?

[Olav Kahlbaum (TRINAMIC)]

There are no known bugs in the StallGuard profiler. It works perfectly with all kinds of interfaces, also with USB (and much faster than with RS232).
Your problem sound like a hardware error. Please check your USB cable first (we noticed that their plugs are often not very good). Also the USB interface on the module, on the PC or on your USB hub (if you are using one) could be broken.
Please counter-check it with a different PC, USB cable or hub.

[Andrew]

Some PCs loose USB connection spontaneously.
For example, a USB mouse suddenly gets disconnected from its software driver. Only restarting the computer restores the USB driver into system.

If you use Windows, this seems to be a software problem. Apply latest security, and other patches from Microsoft. Then this problem will deminish. It won't go away completely though. It is not clear which patch exactly does the job. Windows is unstable as a whole. One driver or DLL will influence the other. Both crash, if one is faulty.

The Stall Guard profiler perhaps does not crash at all. It simply looses the connection to USB. Probalby the TMCL-IDE keps working afterwards. Just the connection is lost.

I presume the same problem will happen to your USB port when it is heavily used with any other TMCL program - not just Stall-Guard profiler. Just send and receive many TMCL commands, and your port will fail. For example run a program in direct mode.
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[mimo]

Hi,

we tested the device with the command "Get actual position" within an endless loop to test the devices interface with heavy activity (USB, direct mode). The program ran about 6 hours bevor a crash (result checksum wrong), Stallguard failed after about 20 seconds.

We solved this problem by using the serial interface. StallGuard has no problem when we use this interface.

[Andrew]

Perhaps you know, that USB with TMCM uses a software driver emulating RS232.
Perhaps that emulating driver has some bug.

The driver might need extra configuration. Did you try it?

In general, the main problem in such situations is a rate of flow of data - either too fast, or too slow, or intermittent. This needs investigation. Seems like a bug in TMCL-IDE.

You did try to send command GAP continuously as a test.

There might be still a difference between GAP and Stall Guard profiler.

In case of GAP command, a microprocessor of TMCM does not have anything much to do. It simply returns. I don't remember though. Maybe actual position parameter still needs to be retrieved from TMC428.

In case of a Stall-Guard profiler, the processor has extra things to do, like retrieving the status of load from TMC428.
That's where the minute fluctuations of time might affect the result. Consider that USB is sometimes faster than RS232. So the period of data exchange is shorter, perhaps the timeout too.
Inside TMCM the motion processor TMC428 updates the Stall Guard value (the load) from driver TMC246 only each full step. So, some durations of steps might simply be longer than the timeout in USB.

Also it is possible that the USB connection is simply not reliable at some rates. Did you try to vary the baud rates?

The other possible fault might be in the USB circtuitry of TMCM610. Maybe it introduces some voltage to TMCM, where it should not, so that it interferes with Stall-Guard specifically. Maybe it interferes on the SPI line between the TMC428 and TMC246 on board of TMCM610.
This is for Trinamic to investigate.

But one indicator is that most problably the connection to module is not lost at all, and the module itself remain perfectly operational. It might even retain the correct count of steps made so far till the fault.
All that happens is that communication fails but temporarily. Does TMCL-IDE continue to operate? If it does not, did you try to restart TMCL-IDE without restarting the TMCM? Does TMCM610 remain operational?

Did you try to install a new Firmware 6.22 for TMCM610 ? Did it improve the problem?

[mimo]

Hi,

[quote]The driver might need extra configuration. Did you try it?[/quote]

We simple used the driver profided by trinamic without changes.

[quote]Also it is possible that the USB connection is simply not reliable at some rates. Did you try to vary the baud rates?[/quote]

How can I "vary the baud rates" when I use the USB connection?!? USB has no "baud rate" besides USB 1.0, 1.1 and 2.0, or am I wrong?

[quote]Does TMCL-IDE continue to operate? If it does not, did you try to restart TMCL-IDE without restarting the TMCM? Does TMCM610 remain operational?[/quote]

The device remain operational in both scenarios.
-After StallGuard hangs, I simple close the StallGuard window (not the IDE!!) and reopen it.
-Inside my programs I simple repeat the instruction and go on.

The problem is: We use the TMCM-610 as control device of a antenna measure table and we HAVE to know, whether the instruction is executed or not. With this error we can not use relative instruction (e.g.: move forward 100 steps several times), because we do not know the result when the device returns this error (did it execute the instruction or not?!?).

[quote]Did you try to install a new Firmware 6.22 for TMCM610 ? Did it improve the problem?[/quote]

We use the newest firmware available for this device (v6.22). Because I updated the device directly when I got it I can not compare the firmware "bugs" to older versions.

Like I mentioned bevor, we solved this problem by using the serial interface.

[Olav Kahlbaum (TRINAMIC)]

Hi,
the USB driver for the TMCM-610 does not need any extra configuration (and it is not possible to change anything there, like baud rates etc.). Please use the latest version of the TMCL firmware in the TMCM-610. Versions prior to 6.18 had a bug that in some cases leaded to loss of data when there was heavy load. This can be a reason for such problems (as the StallGuard Profiler produces much load).