Drive unit error on SF200-02 / AW11-10

[DJR96]

Well, I've been getting my new toy going. Having fixed or bypassed a number of issues I've now come up against this error:-
"E1001(--) PWM signal momentarily stopped"
This occurs when I grab the deadman switch after turning the motors on. So as soon as it attempts to apply any power to the motors.

The "countermeasure" advice it gives is to replace the drive unit.

The drive unit I've learnt is the servo amplifier. Mine has a part #RBX1100.
[Here's one on eBay:- http://cgi.ebay.com/NACHI-FUJIKOSHI-RBX1100-SERVO-AMPLIFIER-UNIT-RFB-/180468030775 ]


Can anyone point me in the right direction?
What components on the drive unit (servo amp) could it be?

One possibility might be because it's now on 50Hz power instead of 60Hz. Could that be it? Is there different drive units to suit the power supply frequency? Or is there a simple setting to change to suit? Or does that not matter at all?

Any help or suggestions would be much appreciated.


[Edit : part numbers]

[DJR96]

No one??
We really need more people on here to make it a bit more active and beneficial to us all.......

I sent an email to a Nachi tech in Australia. He said AW and later controllers have the multi tap transformers to accept any voltage between 380v and 480v and either 50 or 60Hz supply frequency. So the frequency should not matter. Just so long as the voltage connections are correct which I've done.

So it seems either I've got a serious hardware fault in the drive unit, or perhaps the firmware version of the cpu on it is only programmed for 60Hz supply. Perhaps a different firmware or chip would fix it? It would be even better if it were a simple jumper or dip switch setting to change.

Still keen to hear your thoughts and experiences.

[thedude]

Are there any errors that occur when you power the robot up? This error sometimes points to another error that is not currently being displayed. I would check that and also all external safety connections(e-stop, fence, etc)

[DJR96]

Thanks for the reply!

I was getting some other errors.
Some relating to safety circuits, which I've been able to remedy.
I also had a low battery warning in the manipulator, which I have also remedied. I've got a full set of batteries and capacitors ordered. In the mean time I've got one battery powering two capacitors. Only one battery was dead. I reset the encoders, restarted it and it is not giving any more errors at all now except the E1001. It seems to power up fine otherwise.

[thedude]

Any chance that another error is happening when you get the E1001 and its reporting the E1001 as the most recent error? Do you know if the robot worked before you got it? If it used to work, then I bet its not the amp being defective.

[DJR96]

Hey dude,

The robot came from the Chrysler assembly plant at Warren. I seriously doubt they would gut the plant just because one robot died. So one would safely assume it was working when removed.

If there are multiple errors occurring they would all be listed in the Monitor2 log. I did have other errors which I've resolved. Although the encoders are likely way out of position because they were reset away from the "pin position". This shouldn't prevent it from being moveable, although it would probably throw another error when it's moved beyond where the encoder thinks it is. But we're not even getting the motors active to move anything.

I've just received the service and maintenance manual for it. There's a section about calibrating some control voltages. I was hopeful this may be my issue because I have had to change the transformer tap connections.
There's a trimpot on the SR1 and SR3 power supply transformers mounted high on the right side of the controller cabinet. (Oddly the SR2 one didn't have one in mine.)They were close but I dialled them in spot on. Very sensitive trimpots by the way!
The one for the SR3 says to adjust to 5.3vdc, but notes that ideally it should be 5.1v +-0.1v at the encoders. Which will vary slightly depending on how long your interconnect cables are. So I tested and calibrated it at the V axis encoder. Turns out to get 5.1v there it only needed 5.15v at the other end, despite having 10m cables.

All to no avail. Same E1001 error.

So now I'm scouring the rest of the manual looking for more possibilities.
Bit depressing seeing so many troubleshooting flowcharts ending in "replace drive unit" though.......

[thedude]

I understand where your at with this thing, just want to get it going. If you use monitor 2 and check the panel inputs, it will tell you about the safety circuits. Most safety circuits should be in yellow(high input value, fail safe inputs). Also you can turn off the built-in plc under constants-> control constants disable the built-in plc option, this will eliminate any special conditions that chrysler used  in their ladder.

[DJR96]

Yeah, I managed to disable or bypass the added safety circuits. None of that is preventing operation at all now.

In the service manual, one of the trouble-shooting flowcharts is for an E0066 power unit voltage alarm. I'm not getting this error, but one step is asking if the voltage at C1 capacitor in the power unit is above 24v. Mine is 25.7v so when I get a chance I'll look at that in more detail. The AC supply to it is from the main transformer and it has several taps at 1v spacing so I could adjust it there. But I'll check that the rectifier and capacitor are ok first. First job for the weekend...........

[DJR96]

Well,  the 20Vac tap connection on the main transformer was spot on 20Vac, but after the rectifier it was becoming almost 26Vdc. I changed it to the 19V tap which resulted in 23.8Vdc. Much closer to spec.

Unfortunately it hasn't made any difference in getting rid of the E1001 error.


I've also moved the robot arm into all it's "pin" reference positions and done the full encoder reset and correction process. I've got a full set of legitimate numbers and all looks good.

[For what it's worth, the robot doesn't quite tip over if it's not secured (bolted down) and in the pin position.]

But it too has also made no difference. I'm still getting this E1001 error. 

I'm all out of ideas now too. Short of pulling the drive unit out and having a really close look.

The only other remote possibility is a faulty relay in the drive unit. But there is various error codes for that and I'm not getting any.


So I'm at a loss as to what to do now.

[DJR96]

Well, I'm at a dead loss with this issue now.

I've got hold of all the manuals for it and scoured through them for any clues.

I've checked, adjusted, reset, bypassed, or disabled all the following:-

Supply voltage
Checked fuses and circuit breakers
Cleaned inside controller, fans and heat exchangers
All the control and encoder voltages
Replaced encoder batteries and capacitors
Reset encoders
Encoder offset values
Removed add-on parts
Bypassed add-on electrical systems

The LED lights on everything including the relays on the drive unit are displaying as they should.
The brakes are working and manually releasing properly. The cables and connectors all appear to be fine.
Everything seems to be behaving as it should, until a second after grabbing the deadman switch. It won't complete the Motor's On procedure by releasing the brakes and performing the encoder preloading, and therefore I can't get any movement. It doesn't seem to energize anything at the robot.
I'm no longer getting any errors or warnings what-so-ever except for this "E1001(--):PWM signal temporarily stopped" error.
But it's got me stumped.

I'm open to any suggestions at all now!

[bsrr]

The Motors have to be switched ON by pressing Master On and Teaching Ready.Maybe the Motors are not switched on and hence  Error

[DJR96]

Hi bsrr, welcome to the forum.

When you are just trying to move the robot manually as I am, you switch both the switch on the controller and the teach pendant to Teach. Then press the Motor's On button on the controller. That button blinks it's green light and there is a relay or two on the drive unit that becomes energized. It is now ready and waiting for you to grab the deadman switch. It's in full manual mode so it is waiting for you to make the commands. Up to this point it is all behaving as it should as far as I can tell.
But then when I grab the deadman switch there is a slight pause, maybe half a second, and then it just de-energizes those relays, stops blinking the green light, lights up the Motor's Off button and Error light, and throws the error code.
What's meant to happen is that it upon grabbing the deadman switch, it then energizes the motors and moves slightly to preload the encoders. It does this the first time after the controller is powered up to regain full accuracy of the encoders. But mine is not getting that far. Once it's done that the Motor's On green light will be on full time, and whilst holding the deadman switch you should be able to press the various axis buttons and get some movement.

[bsrr]

Do you have TEACHING READY Button on the controller next to MASTER ON?

[DJR96]

Do you have TEACHING READY Button on the controller next to MASTER ON?

I'm wondering if you are familiar with the Nachi AW controller now? My machine doesn't have any controls with those names.

[monty]

Hi
I had similar problem but different error code.
I ended up checking all the connectors by unplugging and re-plugging, the problem fixed itself after I pulled the main board out and put back in. Must have been bad contact somewhere, no problems since.