Home a Kinetix 5500 Servo using current

Hi,

Does anyone have examples on how to home a Kinetix 5500 servo using current instead of a input?

1) move the axis toward your hard stop you want to be home. (probably MAJ) (speed depends on what happens when you crash this hard stop)

2) monitor the current

3) when current breaks some threshold, stop the drive (MAS) and then home it (MRP)

Gomez_ said:

1) move the axis toward your hard stop you want to be home. (probably MAJ) (speed depends on what happens when you crash this hard stop)

2) monitor the current

3) when current breaks some threshold, stop the drive (MAS) and then home it (MRP)

Click to expand...

This but i would use torque.

Thank you I had used current in the past but wanted to know if there was something new.

James42005
Is Torque feedback available on a 5500?

c3markh said:

Is Torque feedback available on a 5500?

Click to expand...

By default it isn't monitored. You have to go into axis properties and check the box for TorqueReference and CurrentFeedback. You will then be able to monitor tags XXX.TorqueReference & XXX.CurrentFeedback. XXX=Axis Name

Also when doing this I've always used a Prox switch close to my hard stop to ensure I'm actually at the hard stop and not reading torque or current increase from a bad spot in an actuator or slide. Many years ago was called in because the homing was off. About an inch before hard stop a bolt had backed out of the linear rail and stopping motion, this increase torque and thought it was home.

Why RA hasn't brought this back into the CIP servo properties is beyond me. As I recall it's an option in the SERCLOSE drives. They do have an AOI for this though which I used on previous project. I recall having to do some tweaking to make it work right. In the end a home-to-torque wasn't repeatable enough for the system we had.

Hello to all.
It's possible to read the current during drive Kinetix 5500 operation and display or capture in the PLC? PLC CompactLogix 1769-L33ERM

OutputCurrent is a standard part of the axis tag. There are a great number of parameters that can optionally read/write from the drive at the coarse update rate by specifiying them in the Cyclic parameters tab of the axis properties.

When I do a "Home to Hard Stop" with Kinetix 5000, I set the torque limits and then use the Axis.TorqueLimitStatus bit to tell that my MVM or MAJ instruction has resulted in the axis arriving at and being stopped by the Hard Stop.

Something I was reminded of the hard way last week is that if you export a *.ACD file to *.L5K text mode and then re-create the project, then the actively-transferred values that come with the cyclic coarse update get reset to all-disabled. At least that's what happened to me on a v32 project.

But the .TorqueLimitStatus bit is automatically updated as part of the ordinary Axis structure, so that wasn't a problem for me. I got tripped up because the bus voltage monitoring alarm was triggering.

Rockwell has an AOI to do torque home for CIP axes. It's a bit buggy and I rewrote it, but you can't just use torque or you will get inconsistent results. You need to set your torque limit to a non breaking value with SSVs, set your position error and velocity error to higher limits to prevent motion faults, also with SSVs, then MAJ until the position error exceeds a soft limit for X time. Once the PE exceeds a limit, then passive Home the Axis to the desired position, and set the torque, position and velocity limits back to normal operating levels. Using this method insures consistent homes everytime, and elimates false homes due to torque spikes.