Ultra 3000 SERCOS Controllogix Overtravel Issue

[Patriot 0]

I am working with a system using a SERCOS Ultra 3000 servo on a Controllogix platform. I have been testing hardware and software overtravel faults, and I have found it to be difficult to recover from them. When I tested a software overtravel limit that I had set, I tried to reset the E16 (software overtravel) via a fault reset pushbutton that activates an MAFR command. The fault did not clear, and I had to go in to RSLogix500 and disable software overtravel limits. Then I activated the MAFR, which cleared the E16 fault. I then had to enable the drive through an MSO, so I could jog the axis away from the software limit. Then I went back to RSLogix500 and re-enabled software overtravel limits. There must be a better way, but I did not see much advice in the AB Knowbase. Does anyone have any experience overcoming this issue?

[lion 0]

first,I must correct your one error.the sofeware should be logix5000.now I think even though it produced one error about overtravel faults,you also can use MAM or jog instruction to move reverse direction.when it left from this overtravel position,you can reset this error through MAFR.beacause you must solve error,or can not clear.You can try it,I think.this error should not cause the servo disable.

[Capple123 0]

We have 44 3000 drives on one of our newest machine. The Builder is working with Rockwell with an issue they ran across. Seem that sometime the software over travel will not disable unless we cycle the power to the drive with the over travels disabled. Rebooting the drives. The concern we have is that the Builder also programed the machine to SSV the Drives on a Periodic task of 10 seconds. Even if there are no changes to be made. We feel this is overloading the drives.

[Patriot 0]

My software still says it is called RSLogix5000. As far as the overtravel, I could not re-enable the drive unless I prevented software overtravel limits from disabling the drive. There is the option to do this under "Fault Actions" within the axis configuration menu of RSLogix5000. Once I set the software overtravel limits to be "status only", I could reset the E16 soft overtravel fault from the Ultra 3000. I could also then jog the axis to move away from the limit. If I did not prevent software overtravel limits from disabling the drive in RSLogix, I could not jog the axis. I am new to this, but I know a lot of other systems that have ways to work around overtravel situations. I have not seen any procedure to do this through the Logix platform. If someone has actually done this, or seen an explanation from Rockwell that I have not been able to find, I would appreciate it.

[b_carlton 61]

We also had to implenent the Disable - Clear - Drive Off Overtravel - Re-enable sequence. You would think that something as capable as the Ultra 3000 would have direction sensitive overtravel for the soft limits. For both the hard and soft overtravel I would like a 'Stop Drive when engaged but allow opposite travel and automatically clear when no longer engaged' mode as one of the options.

[Peter Nachtwey 15]

Usually the positive limit only disables motion in the positive direction and the negative limit disables motion in the negative direction. You don't have the limit switches switched do you? That is an oops. Not only will the limit switches not stop the motion when moving toward the limits but then you can't move the axis to the normal range.

[lion 0]

because I have ever used hard overtravel sensor.When I move to hard limit,I can not move on this direction.But I can use other instruction to move reverse direction.When leave from hard limit,The alarm is clear.

[Patriot 0]

I would have thought that moving in the opposite direction would work. I am referring to the soft limits only. I was not able to reset the E16 fault (soft overtravel) with an MAFR. I cannot do anything unless I can reset the fault and re-enable the drive, and the only way I could see to do it was to first disable software overtravel limits in RSLogix500 temporarily, From some of the other responses from those that have faced this issue, it appears that temporarily disabling software overtravel limits in RSLogix5000 might be the only way to recover. This just does not seem right to me, because not everyone will have a computer connected to the machine to recover from an overtravel this way. I have been doing some more checking using GAM (Google Assisted Memory). I have found something that I have just started to read that shows an example of reading and writing to the fault configuration bits of a drive to disable software overtravel limits for homing. This would be great. I have not read through all of the info, but this looks like it would do the same thing as I have been doing, but directly through the ladder. I will read it and post back here. Edited 23 May 2008 by Patriot

[OkiePC 14]

This is how we had to do things with the predecessor to Logix motion. We did it programmatically though, within the controller program (GML diagrams) by writing to the "control settings" for the axis. I am sure there is a way to do the same thing within your PLC program: 1 disable soft overtravel checking, 2 clear fault 3 enable axis 4 move to a position within the limits 5 enable soft overtravel checking... I don't have any experience with logix motion to describe the details of how to do this, but I would expect that you will find a way! Good Luck!