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Author Topic: CS Labs CSMIO/P-A  (Read 15147 times)

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Re: CS Labs CSMIO/P-A
« Reply #300 on: August 28, 2018, 02:27:40 PM »
Hi
So can you set the encoder resolution or is it Fixed?

Cheers
Re: CS Labs CSMIO/P-A
« Reply #301 on: August 28, 2018, 02:37:55 PM »
Hi,
the encoder in the servo is fixed and the drive is setup to handle the resolution.

The encoder outputs from the drive to the CSMIO are synthesized. They can be programmed at different resolution.

Craig
My wife left with my best friend...
     and I miss him!
Re: CS Labs CSMIO/P-A
« Reply #302 on: August 29, 2018, 05:19:22 AM »
Hi,
finally found the setting.

Note the factory setting is 2048 line per rev or 8192 counts per rev.

Its not clear to me from the table entry that it can be adjusted. The fact that it is  a RW variable suggests that you can set it  but equally the lack
of max or min data values suggest that it is fixed. Either way 8192 counts per rev is useful middle ground.

At max servo speed, 3000 rpm or 50 rev per second, the line frequency is:
Fline= 50 X 2048
       =102.4 kHz
This will be the maximum frequency of the A/B quadrature signals to the CSMIO encoder inputs. 100 kHz is quick but not too difficult. Twisted pair differential
signaling is provided and should work well here.

If your leadscrews are 5mm per rev and your servos are 1:1 coupled to the leadscrews the resolution at 8192 counts/rev is:
resolution (linear)= 1/ 8192 X 5
                         =0.6 um
Sub micron resolution is very good and still the encoder line frequencies are realistic. In short even if the resolution of the synthesized encoder is not
programmable the choice made by the manufacturer is right in the sweet zone with respect to resolution and signal frequency.

Craig
My wife left with my best friend...
     and I miss him!
Re: CS Labs CSMIO/P-A
« Reply #303 on: August 29, 2018, 01:16:23 PM »
Hi Craig

Thanks for digging that out. I think that level of accuracy is way above what I need or could measure. 0.6um is 0.0006mm.
0.01mm is where I am with my dial and vernier gauges. Lol

Cheers Again
Mick
Re: CS Labs CSMIO/P-A
« Reply #304 on: August 29, 2018, 08:51:14 PM »
Hi,
if that is the case, and the parameter is adjustable? then I would set it to 1250 line per rev
which corresponds to 5000 counts per rev.

With 1:1 coupled leadscrews at 5mm pitch then the resolution is 1um, an easy number to deal with.
The steps per unit (mm) in Mach would be 1000, easy. Set the max velocity in Mach at 5000 units/min
ie 5m/min. That would mean that Mach and the CSMIO would demand no more than 1000 rpm
from your servo.
Set the acceleration as high as is practical, excessive acceleration will cause over current events, so you
want to back off by 25% or so from that.

At 1000 rpm and 1250 lines/rev the A/B quadrature signals would be 21kHz, real easy going.

Craig
My wife left with my best friend...
     and I miss him!
Re: CS Labs CSMIO/P-A
« Reply #305 on: August 31, 2018, 12:45:15 AM »
Hi

Found this on scaling in the manual. Section 7.3.4.2 (screenshots below) I think this may be something to do with the resolution of the encoder.
I don't fully understand PUU.


I spoke to S/T yesterday who said the resolution of the encoder is changed via parameter P5-16

P5-16 AXEN
Encoder Increments in PUU Applicable operating mode: PT, PS, V, T Setting can only be changed if power stage is disabled.
PUU -2147483647 0 2147483647 Decimal
s32 RW

Cheers

Re: CS Labs CSMIO/P-A
« Reply #306 on: August 31, 2018, 03:48:20 AM »
Hi Craig

Parameter P1-46 is adjustable from the drive.

Will get back to you later with the acceleration tests.

Cheers
Re: CS Labs CSMIO/P-A
« Reply #307 on: August 31, 2018, 05:28:24 AM »
Hi,
you must have a different manual than I, I haven't seen those pages before. I believe they relate to electronic gearing
and is important in step/direction mode but irrelevant in analogue velocity mode.

P1-46 is the encoder output pulse resolution and is separate to electronic gearing.

Craig
My wife left with my best friend...
     and I miss him!
Re: CS Labs CSMIO/P-A
« Reply #308 on: August 31, 2018, 06:58:19 AM »
Hi,
I've just been looking more closely at the manual I have and the pages you linked are there. I was not concentrating on those as they relate
to pulse input whereas you are planning on analogue input.

You concern is how the simulated encoder outputs (to the CSMIO) relate to the absolute encoder on the servo motor.

Craig
My wife left with my best friend...
     and I miss him!
Re: CS Labs CSMIO/P-A
« Reply #309 on: August 31, 2018, 12:42:19 PM »
Hi

Need to put worrying about the encoder outputs resolution on hold for a minute.

Connected the encoder and Vref to the CSMIO. Seemed to be working ok then tripped the electric and now the drive powers up but seems to be locked with the fan continuously running. Been on the phone to Schneider technical for over an hour who were as much help as my Misses would be. >:( Literally only sent the Z axis home a few times at slow speeds as was having an issue with the homing not working right.

I have not got a clue where to start or what has caused it. Help please!!

Cheers