Kinetix 5500 - Fault <Excessive Velocity Error>

[Ng Haireen]

Hi Guys,

I need your various suggestion and helps on this issues. Past few days we facing an issues whereby the gantry of Z-axis which using the Kinetix 5500 servo drive straight crash down on the conveyor. The fault was Excessive Velocity Error and the first thing we took a look was the teaching and the speed. Somehow the teaching value of the motor and the speed was alright, we are running the axis on 100% speed. We have no idea the fault might be on the wiring or it might be the acceleration of the motor speed. We use to run this machine onsite at various customer, and this happens past few days. We run out of idea and we will be very much appreciated if there is any helpful idea could be bring up to.

Steps taken so far;

- Verify encoder value

- Checked teaching position

- Verify speed,acceleration and deceleration value was correct

- Power motor connector was shielded

 

[Armadillo852]

Did you verify there is not a mechanical bind? 

[Ng Haireen]

Armadillo852 may i know what is mechanical bind ? Because im quite new to these stuff 

[Jobbe9000]

Hi Ng Haireen

If you look in the fault log, you will see that about 30ms earlier than the velocity error, you actually had a "Soft Travel Limit - Positive" fault.
This fault will throw an "Planner stop" exception, which tries to stop your motor with the maximum deceleration specified in the "Planner" category.

If this deceleration is too steep or hard for the drive, then the "excessive velocity error" will occour.

I think you should look at your setup to see if you are going very close too your soft limits... Especially when you say that you utilize 100% of the motors speed. 
The motor will have no "extra power" to compensate if it gets alittle behind, and it might end up overshooting.

So to summerize, you should check what values you have in the planner category, and check if it is possible not to move so close to the soft limits.

[Ng Haireen]

Hi Jobbe9000

Thank you so much for the replies. I really appreciate your help and your opinion, will take some action based on your suggestive idea.