problems when two pololu jrks are plugged

[runningwild82]

Hi, i've got two 12v12 jrks connected to two distinct wiper motors and two distinct power supplies, that function perfectly when plugged one at a time. But when i connect both of them to usb ports then strange things happen, infact if i give a manual input to one of them in the jrk config utility both motors run, at first the right one followed by the other motor that wasn't supposed to move and one of the jrks... after that sometimes one of the jrks gives error and disconnects.
Both the jrks are configured to run in usb dual port mode, one with device number 11 and the second with device number 12. In device manager they appear as com3 and com8 (command ports) with the ttl's ports com4 and com9. Tried to play with the com ports in device manager changing bits per second, parity and things like that but had no luck.
The jrks are not connected one to another in any way.
Sorry for my bad english and thanks in advance for your help!

[sirnoname]

Dont't touch the device manager.
Don't touch the pololu factory default.

Two comports are ok, make a screenshot of the interface setup after you did the above.

[thaparser]

Hi, i've got two 12v12 jrks connected to two distinct wiper motors and two distinct power supplies, that function perfectly when plugged one at a time. But when i connect both of them to usb ports then strange things happen, infact if i give a manual input to one of them in the jrk config utility both motors run, at first the right one followed by the other motor that wasn't supposed to move and one of the jrks... after that sometimes one of the jrks gives error and disconnects.
Both the jrks are configured to run in usb dual port mode, one with device number 11 and the second with device number 12. In device manager they appear as com3 and com8 (command ports) with the ttl's ports com4 and com9. Tried to play with the com ports in device manager changing bits per second, parity and things like that but had no luck.
The jrks are not connected one to another in any way.
Sorry for my bad english and thanks in advance for your help!

Your wiper motors may be wired such that they leak current via the chasis. Make sure they aren't wired to their case which is in contact with the chasis, you may need to open them up.

[runningwild82]

@sirnoname: this is the interface with the default settings

@thaparser: you may be right as my wiper motor heads are screwed to the chassis... but now that i think maybe the body (who has negative polarity) of one of the motors touches the chassis too... maybe could that be the cause of my problems? btw i go to check it out!

[runningwild82]

ok there's some leakage from one of the motors, infact if i connect both the jrks but supply only one of them with power the unsupplied motor moves too... i'll try to find the leakage and keep you informed! Thank you!

[sirnoname]

Of course a screenshot of "interface setup" of X-Sim Converter!

[runningwild82]

edited my previous reply as i think i've found the problem...

@sirnoname: i've not tried my setup in x-sim yet as my problems comes from the jrk config utility, so i think i have to fix things before moving to x-sim!

[runningwild82]

ok i've isolated one of the two motors, to isolate the other would require me to disassemble most of my setup so before doing this i would like to understand if that could be the solution of my problems...
now with one motor isolated from the chassis there are no more interferences between motors, but still one of the jrks gives error like 0x1f failed to set target or something like that, or sometimes error in getting firmware from device... this happens only if both jrks are plugged to usb and powered, if i power only the one that gives issues it will run perfectly...
now my question is: if one of the motors is isolated (the one controlled by the jrk that gives errors) how it is possible that there are still interferences when both motors are powered? even if one motor leaks current via the chassis, the isolated motor should not receive power leaks... so why the jrk goes crazy?

[runningwild82]

i've found out that current leaks are no more a problem, infact i've tried to control the jrks with two distinct pc's and all goes fine! but as i plug them together to a single pc then one of them gives 0x1f errors (control transfer failed) if triggered after the other one.... i'm just going crazy, does anybody have a clue about that? thank you so much!

[thaparser]

I too have 2 jrks that behave differently, not the way you mention.
In the xsim converter interface, the program module has some option to control the frequency the controllers are fed with commands. Try reducing the flow of commands maybe you have a USB bandwidth issue. If I use the default settings on my setup, one of the jrks keeps disconnecting and it is not the same every time.
Please post the output setup screen in xsim converter as sirnoname mentioned.
Good luck!