Haas VF2 - Alarm 142 A motor Z fault

Hey Guys,

Went to do a setup with an HRT210 4th on our older (94ish?) VF2. Connected the 4th and powered up the machine. Got an Alarm 142 when trying to home the A-axis. I can move the 4th exactly 1.000 degrees before it alarms out.

This setup worked the last time it was used.

My first thought was bad connections or a bad cable. Tested continuity through the cable and the connection on the back of the machine. All good. I'm suspect of the 4th unit itself at this point. Bad encoder?

Brought in an identical 4th from another machine and tried it out. It doesn't work. Tested the same 4th on our '95 VF0 and it works fine. I figure ok, it must be the servo board. Swapped the board from the VF0 to the VF2. The same board and 4th that worked with the VF0 do not work in the VF2.

Not sure what else to look at.

Any suggestions are appreciated.

Thanks,
Mike

Quote:

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Originally Posted by Mike8500

Hey Guys,

Went to do a setup with an HRT210 4th on our older (94ish?) VF2. Connected the 4th and powered up the machine. Got an Alarm 142 when trying to home the A-axis. I can move the 4th exactly 1.000 degrees before it alarms out.

This setup worked the last time it was used.

My first thought was bad connections or a bad cable. Tested continuity through the cable and the connection on the back of the machine. All good. I'm suspect of the 4th unit itself at this point. Bad encoder?

Brought in an identical 4th from another machine and tried it out. It doesn't work. Tested the same 4th on our '95 VF0 and it works fine. I figure ok, it must be the servo board. Swapped the board from the VF0 to the VF2. The same board and 4th that worked with the VF0 do not work in the VF2.

Not sure what else to look at.

Any suggestions are appreciated.

Thanks,
Mike

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I would start by comparing the parameters for the HRT 210 between the two machines.

Is that necessary? No parameters were changed since the last time our original setup was working. We used it probably a couple months ago, disconnected it and pulled it from the machine to free up some table space. Hooked it back up this week and it gave the 142 alarm.

If there is something to be gained, I will definitely do it.


Thanks,
Mike

Ok. I compared the parameters for the A Axis on both machines. All identical.

Quote:

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Originally Posted by Mike8500

Is that necessary? No parameters were changed since the last time our original setup was working. We used it probably a couple months ago, disconnected it and pulled it from the machine to free up some table space. Hooked it back up this week and it gave the 142 alarm.




Thanks,
Mike

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So you have a rotary table that does not work in one machine but works in another = nothing wrong with rotary
Servo drive swap from working machine to non working machine does not change anything = nothing wrong with servo drive

Quote:

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Originally Posted by Mike8500

If there is something to be gained, I will definitely do it.

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What you have to gain is a working rotary table!! That is the goal, correct?!?
Why would the parameters change? I have no idea. Bone head operators changing something they do not know, sabatoge, or plain human error. I don't know your shop or who has access to what. I can only speculate on the information that is presented.

Your other options are to start throwing money at the problem. Change out some boards, cables, call in a tech, etc.

Check them or don't check them makes no difference to me, but you asked for suggestions, so here they are.

Good luck!

Quote:

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Originally Posted by haastec

So you have a rotary table that does not work in one machine but works in another = nothing wrong with rotary
Servo drive swap from working machine to non working machine does not change anything = nothing wrong with servo drive


What you have to gain is a working rotary table!! That is the goal, correct?!?
Why would the parameters change? I have no idea. Bone head operators changing something they do not know, sabatoge, or plain human error. I don't know your shop or who has access to what. I can only speculate on the information that is presented.

Your other options are to start throwing money at the problem. Change out some boards, cables, call in a tech, etc.

Check them or don't check them makes no difference to me, but you asked for suggestions, so here they are.

Good luck!

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I have two rotary tables that work in one machine, but not in the other. I don't believe there is anything wrong with the servo drive since the swap did nothing. As stated above, I did compare the parameters 15 min ago, and they are all identical.

This is a smaller shop, with only three other guys using this machine, they all know better than to fiddle with parameters, and I've spoken with all of them about it.

When I said is there anything to be gained, I meant knowing that no parameters had been changed since the last time the setup was used and worked correctly.

I'm wondering if I can check the A-axis encoder signal and see if it differs from machine to machine. I don't suspect the 4th, the cable, or the servo drive at this point because of the checks already done. It appears to be something inside the machine beyond the servo driver that is not reading the encoder feedback.

Took this from http://diy.haascnc.com/sites/default...11_English.pdf


142 A-AXIS MOTOR Z FAULT
- Encoder marker pulse count failure. This alarm usually means that the encoder has been damaged and encoder position data is unreliable. It can also be caused by damaged motor cable or a loose encoder cable connection on motor or encoder input on the Mocon PCB. (Mill) Check A-axis
cable connection on side of electrical cabinet.

I'm going to see if I can figure out where this connection is.

Does anyone know how to check the actual encoder input (maybe in debug mode?)

Ok. I figured it out, at least I think. I found the connectors on the MOCON board that deal with the A-Axis. I removed the cover to get access to the board, removed the top level board, then removed, inspected and replaced the two connectors (one goes out to bulkhead fitting on cabinet, the other goes to the Servo Drive Board). Put everything all back together and it is now working. Must have been a poor connection.

Glad you got it sorted out!
Well done!:cheers:

Nicely sorted!
Gary