Host Engineering Forum
General Category => Do-more CPUs and Do-more Designer Software => Topic started by: DLTimmons on May 01, 2023, 07:45:29 PM
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I trying to do a simple feed and cut operation using AXPOSTRAP with encoder feed back. I take the .CurrentVelocity and write out to an analog output to run the drive. My encoder is hiting target and fires a cut signal. I used this with CTRIOs in the past with good results. I starting with real slow moves. when I speed the feed up my encoder still saying I made the same move but the material is much longer as much as 20% longer with same encoder counts.
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Update
Made some headway today it mostly scaling of drive command. Still seeing some thing strange ever now and then it over shoots I know over shot it send a negative command to the drive the drive is slowly running reverse but the current position is counting up not letting is get to position but getting farther way from the target
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Things I would check:
Using High Speed Input for encoder feedback in AXCONFIG for that axis and:
You aren't using quadrature.
You haven't changed the default HS input filtering to be fast enough.
Your encoder signals aren't toggling at sufficiently high or low voltages.
You have a bad encoder signal in some other fashion.
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Yeah I was wondering about quadrature as well. Wonder what the default plc channel config is.
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Made more progress today. Had to unhook the shield from the encoder was get a lot of noise in the encoder input I rerouted the encoder cable back to the BX-DME1-18ED13 was't till I disconnect the shield that the noise went away. Now that the noise is gone I have to get the drive to move the motor at low speed to hit target Control techniques M600 and a Baldor RPM series motor used this motor with good luck in the past with and old H2-CTRIO. So I feel it just getting the drive parameter right now.
Yes encoder feed back to Axis1
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Made more progress today. Had to unhook the shield from the encoder was get a lot of noise in the encoder input I rerouted the encoder cable back to the BX-DME1-18ED13 was't till I disconnect the shield that the noise went away. Now that the noise is gone I have to get the drive to move the motor at low speed to hit target Control techniques M600 and a Baldor RPM series motor used this motor with good luck in the past with and old H2-CTRIO. So I feel it just getting the drive parameter right now.
Yes encoder feed back to Axis1
The H2-CTRIO inputs were much slower and would tend to reject noise.
BRX high speed inputs are very fast and will pick up noise the CTRIO never would, but you can tune the filters to make them respond however you want.
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On the AXPOSTRAP what controls the decel rate seem to take long time to ramp to a stop much longer the decel Parameter
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Found the issue had the counts per second way off. It's working just like we need now. :)