Re: Out of Estop.. BUT

> imranjawaid@e... wrote:
>
> > > Well, the jerky motion is strange. How does this amp get

velocity

> > > feedback? Does it take the encoder signals, or is there a tach?
> >
> > The Amp Drive have three connectors
> > CN1 -( Gets the DAC input <------- STG2 card)
> > CN2 -( Get the encoder input --------> amp drive)
> > CN3 -(Amp drive Sends the encoder singnals to the
> > STG2 <-----Amp driver, i.e A+/- , B+/- , Marker +/- without the
> > encoder 0v & 5V opartion voltage)
>
> Ah, yes, instead of a DC tach, it uses the encoder for velocity
> feedback. The problem is it has no velocity info between encoder
> pulses, and the velocity info it does have gets 'bumpy' when the
> speed is extremely low. My servo system, with DC tachs, can go
> down to about .01 IPM before the stick-slip of the table overwhelms
> the tach signal, and it starts to bump. This is so slow, you really
> can't even see it, but you can read it off the position display.
> The only way to do better is to go to a finer resolution encoder.
>
> Matt Shaver and I tossed this problem about for some time, as
> he wanted me to design an encoder to tach converter. My read
> was that it would be VERY hard to do, and get both very fast
> update at high speed and freedom of fluctuations in the output
> at very low speeds. My servo system has meaningful bandwidth
> up to sevral KHz, and so the delay of the conversion would have
> to be kept very low. This is a killer digital filtering problem,

and

> is probably totally insoluble any other way.
>
> Jon

Finally i got rid of those jerky motion.I've looked in to manual for
AC drives and there are vibration knobs on the drive.Finally tuned
it.The motor is smooth.

I also done the zero setting of my motor by joining COM and Pulse
Input wires and adjusting Zero setting variable resistor on the drive.
But when i connect it to the STG2 card it give me rotation.I checked
tthe DAC0 input from STG2 card with multimeter and it gave me 0.01V.
I also tried counter it with 0.085 V from EMC TESTING and it stopped
moving.
So how can i remove that 0.085V from STG2 DAC0 ?

Another thing. The EMC can read encoder signals upto +/- 0.3 V , If i
go higher like 0.4V it stops reading .

The servo gets hot when it moves on max rpm i.e 3000. at +/- 10v.Is
this behaviour normal?

Imran