Ultra 3000 initialization

I ran into a problem today with an Ultra 3000 indexing drive that had been performing OK. I needed to change the direction of rotation for increasing encoder count. This was in the drive window of Ultraware. Once I made the change, the drive would not initialize. It would fault at the end of the initialization displaying error code E39 which is defined as "self-sensing commutation error".

Two questions:
1. Since the motor had been working properly prior to the change I figure the power and feedback wires have to be connected properly. But when you change the "motor forward directioon" parametyer in Ultraware, does anything else need to be changed along with it?
2. One of the remedies for the E39 error code in the troubleshooting section is to increase the self-sensing current. I don't see in Ultraware where to do that. Is it the "Home current value" parameter in the Homing mode configuration window?

Motor is MPL-A1520U-EJ42AA
Drive is 2098-DSD-005X

Edit:
Another question: In other drives I've worked with, there is a parameter called "backlash compensation" or "reversal compensation" which tells the drive how many encoder pulses to ignore whenever the motor reverses direction. Is there anything comparable in the Ultra 300 series? If so, what do they call it?

I've never had this particular problem but in the Ultraware manual (http://literature.rockwellautomation.com/idc/groups/literature/documents/um/2098-um001_-en-p.pdf) there is reference to a "self sensing current" parameter that can be adjusted in the Motor window. Seems to only be applicable to certain motors.

I am fairly certain that the "home current value" parameter is not what you are looking for--this allows you to home a linear axis by hitting a hard stop.

Things that ought to be simple aren't turning out that way with this Ultra 3000.

Today's problem: I had always planned on using hardwired overtravel limit switches on this application, but until they weren't set up. I only had the home switch wired in. Today I wired them up and configured two of the Ultra's discrete inputs as positive and negative end of travel. After I did, I started getting error code E12 when trying to home the axis. It didn't matter whether I wired the switches NO or NC.

I tried just configuring the negative OT switch. Command a find home and the axis goes to the home switch and reverses direction then faults (E12) as soon as it clears the home switch.

Can anyone point me to a manual that describes homing and hardware overtravel switches in more detail than the Ultra 3000 installation or integration manuals or the Ultraware help files?

Based on your testing, I'm guessing that the negative OT is at the end opposite of the home switch. In other words, when you're going home, it's in the positive direction. If that's the case, then that's why it's not erroring (is that a word?) until after it reaches the home sensor. It can move towards home because the + OT is not enabled, but once it tries to move off the home switch (in the negative direction), it thinks it has reached the - OT switch.

I haven't played with Ultraware, but can you view the status of the OT switches? Are they on? I'm pretty sure they should be wired NC. I've never seen a drive that used NO switches. Somehow the drive is not recognizing that the OT inputs are on. You're definitely enabling them, because you're getting the fault(s) when they're enabled.

Are you sure you have the input polarity right on the switches? Are these 'real' limit switches with physical contacts, or proximity sensors?

Hey, at least the weather's nice!...



-Eric

I'm using proximity switches wired NC. I can see the signals with Ultraware. With no target in front of a switch, Ultraware shows the input on. Put a target in front of the prox and Ultraware shows the input off.

When I had both switches configured, it didn't matter whether I had both of them sensing their targets or neither of them sensing their targets. Either way, I got the error as soon as I tried to execute a homing routine.

When I switched to a single OT switch, the OT switch never changed state, just the home switch. At that point I decided it would be more productive to try to find a better writeup than to continue trial and error testing.