Re: servotogo-problems

Jan wrote:

> It is to say that I'm back to where I was (only the A7 bit is
> still initialised to = 0 but I can toggle it with the Svg-soft).

I still don't understand this, my limit switches are not hooked up,
and I have been able to set the software to believe everything is
OK.

> So now when starting up, go out of E-stop, machine on, Dac NOT attached;
> when turning the servo, the decoder is read in all the three states,

I don't understand all 3 states. Do you mean all 3 axes?

> giving
> an error when travelled distance > error in the inifile (this is ok). On
> connecting the dac (servo enabled is done externally) and performing a move
> say Y+0.01, the servo is turning, decoder is read to 0.006 than stops
> resulting in a servo running away faster and faster ( the latest is ok)

OK, either the encoder phase or the motor phase is backwards. If the
position readout changes in the correct direction when turning manually,
then reverse the motor wires. If the readout goes the wrong way, reverse
encoder A and B phase wires.

> but
> why do the encoder stop reading after ,006 mm of travel?

There is a bug in TkEmc, due to it being developed and tested with steppers.
The old Xemc could show either actual or commanded position. When reading
actual position, you can see the numbers flicker back and forth a single count
every once in a while, when the servos are active. TkEMC has the buttons
to select these readouts, but you only see the commanded position (which can
lie, especially when the servos go open-loop).

> Some ini-settings?
> So when pressing F1 the servo stops (ok) but then when manually moving the
> servo no encoder is read. When restarting the soft everything is like it was
> before!

Once you go into E-stop, the display should read actual position, even with
TkEmc. But, try Xemc, and see if it responds differently.

>
> I changed the encoder signals from differential to single input (from A+,
> A-, B+ ,B- to A+, B+). Nothing changed.
> Having a look on a osciloscoop it told me that I just have 0-3volt on A+ and
> B+ and NO REF-signal. Could this be the problem? I do not know if 3volt is
> enough since TTL is 5 volt and or if EMC takes the reference signal into
> account.

Oh, there may be a problem if it thinks it is getting the index (or ref) signal
all the time. So, try changing the index polarity setting in the .ini file.
I have not seen that to be a problem on my system.

Jon