adccommunitymod (AutomationDirect) asked a question.
Maximum Status Monitor Values
Created Date: September 25,2012
Created By: kevgig
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Hi, I have a 3kw SVA2100 amplifier connected to a SVM-230(B) motor, set up for relative position mode. We use status monitor P0-04, set to 01, for reading back absolute position (revs). What is the maximum value that can be returned from the status monitors (65535?)? Once the maximum value is reached, how does it roll over (negative counting down, back to 0, etc)?
Created Date: September 25,2012
Created by: kevgig
Just answered my own question.
The maximum value is 65535.
If I were to cross over the max of 65535, I would start getting negative numbers like -65535, -65534, -65533, etc., until I cross 0 and start counting up again 1, 2, 3, etc.
Created Date: September 26,2012
Created by: Tinker
Just answered my own question.
The maximum value is 65535.
If I were to cross over the max of 65535, I would start getting negative numbers like -65535, -65534, -65533, etc., until I cross 0 and start counting up again 1, 2, 3, etc.
I'm curroius how you found that answer?, while I suppose someone could design a system that worked that way, I can't imagine why anyone would.
A 16 bit signed integer has a maximum value of 32,767. While an unsigned word does have a maximum of 65535, when it rolls over it goes back to zero, to have a signed with a maximum of 65535 one would need 17 bits, on a PLC one could use a word + a discrete bit for the sign (though math might be difficult), but how would the SureServo do it?
Created Date: September 26,2012
Created by: kevgig
A 16 bit signed integer has a maximum value of 32,767
Sorry,
Your right. I was looking at the value coming off my servo as a decimal as opposed to a signed decimal.
My original question stems from trying to keep accurate counts using revolutions as my main reference.
What I have come up with works well, but I am worried that what I have come up with will break if the revolution count ever goes negative. The machine using said servo has the ability to be paused in the middle of a position move. So what I do is keep track of revs at start of move, revs done during move and revs left to go. That way, if I encounter a pause, I can resume the move with the correct # of revolutions.
I have yet to figure out a good way to deal with the servo revs going negative. Using the comparator doesn't seem to work for detecting a negative # (maybe I am doing something wrong?). The only other way I can think of for detecting negative revs would be to check the 16th bit (1 =negative, 0=positive), and do my calculations accordingly.
I realize the servo has a pause feature, but it will not work in my scenario.
Created Date: September 25,2012
Created by: kevgig
Hi,
I have a 3kw SVA2100 amplifier connected to a SVM-230(B) motor, set up for relative position mode.
We use status monitor P0-04, set to 01, for reading back absolute position (revs).
What is the maximum value that can be returned from the status monitors (65535?)?
Once the maximum value is reached, how does it roll over (negative counting down, back to 0, etc)?