hi all ,
im trying to get 3 servo motors to spin a 360 with variable increment angle to 1 degree accuracy. the accuracy is compulsary to be 1degree.

In simple words, moving motor from 0deg to 60deg in 1deg increment and then from 61deg to 120deg in 3deg increment and there onwards do up to 360deg with 5deg increment.
The increment can be in any order, the above is just an example, but the minimum increment input is 1 degree. and fractional increments are not wanted i.e motor does not need to swing in half or quarters.

im using micrologix 1500 plc, with RS logix 500 and Rslinx.

i cnt get the motor to do multi increments, it starts at 0, does 5deg increments al the way to 360.. has anyone done something similar to this?

can somebody help?

thanks

Fusion,

I have not worked with servos all that much but it sounds like to you might look at the counts coming back from your encoder [assuming you have one] and do compares to determine where you are at in the cycle.
So if you have an encoder with 360 counts/rev then
if encoder counts are equal to or between 0 and 60 increment 1 deg
if encoder counts are equal to or between 61 and 120 increment 3 deg
if encoder counts are equal to or between 120 and 360 increment 5 deg

Hope this helped.
Bob O.

It is easy to do. The term you are looking for is relative move. You can make 1 ,2, 3, 4, 5 or 6 degree relative moves for each increament of 60 degrees.
Now why? What are you really trying to do? If you are trying to do some form of gearing there are better ways.

yea tHAt SOUNDS alright. Im trying to measure light intensity from different lamps at different angles and then plot the reading which is recored by a photodiode. the lamps are mounted on the motors which spin the lamps to a user specified angle as mentioned above.

THe system im using iis AB ulogic1500, and rslogix500. it dsnt seem to work very well. im not a gud plc programer as this is one of my first projects but it getin there slowly.