Support & Engineering

The following solutions and fault finding FAQ for Rockwell Automation servo systems like Ultra range, Kinetix range and IMC class range.

Common problem that can happen on servo drive systems is a position error fault (Error 19).

Cause: The difference between the servo command position (requested position) and the actual position (feedback from motor) is greater than tolerance allowed.

Solution: Assuming the servo has been running for some time. First check that there is no other faults like encoder lost, loose wiring or connectors. Then the most like cause of a position error fault is an mechanical issue. Ask what has been changed and then inspect the servo load for tightest, jamming, load change (increased product, increased inertia), faulted bearings, hot gearbox.
If servo system is new or the load has changed, then it will need better tuning or retuning and checking that servo sizing is correct & matched.

Upgrade or design from new a Flying saw (flying shear, cut to length, rotating knife) application.

Best option: Motion Servo system is best suited to this application, giving very good accuracy, repeatability, dynamic control options like cutting a sample (test) length on the run, operating speed linked to master line speed, multiply cutting profiles can be linked to a production schedule system.

Solution: Use integrated motion servo control system, that is programmed with electronic cam profile control. The axis cams will need to be dynamic with pending ability.
Example is ControlLogix and Kinetix 6000 combination giving machine and axis servo control together.

Bumpless switching between Position mode and Torque mode during machine operation.

Requirement: Your process requires positioning of the product, then during the operation you require pressuring of the product or apply a tension to the product (torque mode). The following method avoids position error faults.

Solution: Use integrated motion servo control system, that is programmed with ramps that change from position mode to torque mode giving bumpless load transfer. Have developed a system using ControlLogix and Kinetix 6000 servo drives. This servo system is currently running 24/7 with an average cycle time of 80 seconds. The process draws in set amount of product (positioning) then presses out the water to a requested density (volume/size). During the pressure stage can have time limits set, maximum torque, and distance travel limits. Once the pressing is complete the new product is moved to reject position (back in positioning mode).

Rockwell Automation Kinetix 6000 servo drives getting random or unrelated faults/errors.

Symptoms: The servo system is running normaly, then a servo fault occurs which you check out and find no obvious faults or problems. Some times you can leave the servo off-line then later the servo system restarts ok, and runs for some time.

Solution: I have had this issue a number of times on different Kinetix 6000 integrated motion servo control systems. Spent many hours checking the servo drive modules, motors, cabling, sercos, axis settings to find no issues. With my last client to have this problem, we do the usuall thing of checking, confirming setup/parameters etc. and finally we decided toreplace the axis module with another new axis module. Just before replacing the axis module we did something simple, and the servo system successfully restarted. Monitoring the Kinetix servo system for 3 months now with no faults. I will update you with any new developments

Any questions or support required do give Andrew a ring on 021 784147. Andrew is based in Auckland, New Zealand and is mobile. More automation solutions will follow in due course.