Newly acquired Kawasaki UX150 with C-Controller

Quote from kwakisaki

Regarding JT5 error:
You may have tight gearing on JT5 and she may just require 'exercising' considering her age so can you jog JT5 in teach mode at all across all or any speed ranges

At the moment I'm unable to jog the robot at all due to the encoder errors, unless there is a workaround?

I did move it manually and it did not seem that hard, especially compared to jt5 and jt6.

I was planning on doing a maintenance anyway, is there a mechanical maintenance manual available somewhere, I did search quite a bit and was not able to find one...

I've found a replacement board on Radwell, never ordered anything there, is it a good source for parts ? Also they offer a few options: new in Kawasaki packing, new in Radwell packing and refurbished (most expensive to least expensive) is it worth the extra money to get a new one ?

Also, I've noticed these errors popping up during the power up of the robot;

-1516 encoder data abnormal jt4

-1511 encoder battery voltage low servo A

I didn't pay attention earlier a they always cleared during startup but now that I've noticed it's definitely weird...

The batteries have an awfully long delivery time I ordered some but is there a workaround or alternative to replace the cells and re-solder ? The cells themselves seem to be obselete and quite hard to find...

What was pushing me towards 1GB is the testing done between 1GB and the robot's connectors + the connector swap on 1FG, but that doesn't exclude a fault between the connectors and 1FG or on 1FG itself... I'll focus on testing that as well.

What somewhat pushed me to be suspicious of 1GB is the previous overcurrent issue, but I'll exclude everything else first. Altough I do still think of buying a replacement...

Yes that is the batteries I have ordered but the fastest delivery I found was 1-3 weeks other than ebay that I can't use anymore.

I ordered some lithium batteries and I'll do the same as you, will be a great saving in the long time.

Quote from kwakisaki

FYI - Encoder low battery voltage warnings:
- Servo A warnings relate to major joints 1,2,3.
- Servo B warnings relate to minor joints 4,5,6

Yes I had guessed that was related to CPU A on 1GB, it's interesting to have separate batteries per 3 encoders but have to replace both batterie at the same time

I'll keep you updated when I've done my probing tomorrow.

Well my batteries are definitely dead, like 10mV dead. I've checked the board for continuity between cn1-6 an cn8. I also checked the voltage on cn1-6 with the controller powered on and had 4.9v so nothing abnormal there. I have a few test points on the board, I tested the obvious ones and voltages in the expected ranges. The voltages on tp4(bat) and tp3(+5B) I could not make sense of but knowing the state of the batteries it was to be expected.

Also there is one more thing I've tested and that's moving jt3 by hand with someone releasing the break to check if the position would still change on the teach pendant. I had zeroed it prior to moving and had absolutely no change after moving in about 20 degrees.

I'm now going to test the continuity between X3 and the 1FG-CN1-6.

Can't wait to get the batteries set up for further testing.

I've now tested 1FG-CN1-6 (pins 1 and 2) and I have continuity and no shorts to X3 control box side. Maybe the error was caused by the extreme battery discharge state ? We'll see once I've replaced it.

So here's a quick status update on the state of the jt3 encoders error at this time:

• Errors related to encoders pop up on startup, but the ones on jt3 do not clear.
• Verified continuity and no shorts from 1GB-CN2 to 1FG-CN1-6.
• Tested swapping 1FG-CN3 and 1FG-CN4, error remained on jt3. Pretty much eliminating the possibility of the issue being the encoder or robot side harness.
• Tested the 1FG battery, which is beyond dead.

Therefore, the remaining possibilities would be either some weird errors caused by the extremely low battery voltage or a defect on the control box side, likely the 1GB board as the unit-A error led lights up. Let me know if you have other suggestions.

Thank you and have a good day.

Quote from kwakisaki

Other OEM's do something similar but choose to use completely separate cells instead of an assembly. Which introduces possibilities of single cell changes at infrequent times.
Kawasaki choose separate cells, but assemble them in a pack, so they are ALL replaced at the same time when ANY battery alarm is triggered from the servo board CPU's to ensure regular maintenance for all encoders and reduces the downtime.

Yes I've noticed they are wired in parallel anyways, my first assumption was there was two seperate circuits for unit-A and unit-B battery. Which would be a bit of a d*** move, forcing you to replace both batteries whenever one of them was low voltage. But since they are wired in parallel they discharge at the same time so it's just the low voltage detection that's seperate between A and B, so if any of them pick up the low voltage error, it means both batteries need replacement anyways.

Quote from kwakisaki

I hope you have not been 'hot swapping' as this can spike the encoders and permanently damage them and possibly damage the 1GB board too.

Nope, I only ever swapped them with the controller unpowered.

Quote from kwakisaki

Have you actually measured the supply to the encoder at JT3 end?

No, I only tested on the 1FG board, as I was convinced a problem after the 1FG board on the robot side was unlikely after the swapping test.

Quote from kwakisaki

Have you swapped JT3 encoder harness at the encoder end and carried out a brake release and moved JT3 arm and seen the encoder/position values change on the axis data you have swapped to?

No, I only tried swapping the connectors with the controller unpowered. I then powered up the controller and noticed the error stayed on jt3. Tried to clear the error a few times, which would not clear and remained on jt3. The powered off and put the connectors back in their original positions. I did this two times to to be sure.

I guess I'll be trying that as well to make sure the jt3 encoder works properly. Also checking the voltage directly at the encoder plug.

As I mentioned yesterday, I went and tried the swap and move. I swapped 1FG-CN3 and 1FG-CN4, cleared the error, it remained on jt3. I zeroed jt4, released the break on jt3 and moved it. I observed the angle on jt4 moving up and down as I physically moved jt3.

I then checked the voltage on the jt3 encoder cable, measured 5V.

I also tested for continuity between the encoder plug (yellow and white wires) and got continuity and no shorts to X3 control box side. As expected after the swapping test.

So unless I'm mistaken this removes any possibility of a problem on the robot side and pretty much points to 1GB being the culprit doesn't it ?

I received the batteries and they are now installed, no more encoder battery error on startup.

I noticed I had not entirely followed the test procedure you advised so I test again today and this time swapped on the encoder end, had the same results; encoder registering movement as jt4 when I moved jt3 and nothing on jt3 when I moved jt4.

I did have the encoder data abnormal jt4 again after testing today, so I guess that was due to the swapping test which makes sense.

Sidenote: I went ahead and bought an rs 232 null modem cable.

Hello Kwakisaki,

I had that idea as well so I went ahead and did that yesterday, I moved the controller really close to the robot and with a bit of difficulty I managed to test for continuity and no shorts from 1FG-CN3 to 1GB. I have the troubleshooting manual but did not see the pinout on there, is it in another chapter than 3 descriptions ? I see the connectors and their roles but not the pinout.

Anyway I managed to find them with the DVM and put a little dot next to the corresponding solder points. There's a friend of a friend that's apparently really good at testing PCBs, so I'll hand it over to him.

I also jumped on a 1GB board I found for pretty cheap and not far (scheduled to arrive next Monday at the latest). However I was at home and during my compulsive order and realized I had ordered one with a different serial number

I ordered 1GB-74 50999-1806R10 instead of 1GB-74 50999-1650R10 hopefully that doesn't matter as long as the switches are in the right position

I'm getting really eager to be able to move the robot and perform maintenance. I want to make sure I can trust the robot before starting to experiment and learn to program for it.

Hello everyone !

I have great news ! I replaced the 1GB board after swapping 1GM and resoldering a condenser that had been torn off during shipping and the controller started with no errors other than the missing interbus connection. I re-zeroed the robot and I'm able to move it with the teaching blocks menu. I also have not had that jt5 over current error up to now.

I'll now be performing a maintenance, is there a manual where I can find the procedure ?

I'll also bring a computer to plug in so I can get everything set up to start running programs.

Again, than you a lot to everyone and especially you, kwakisaki !

Thank you for the manual and praise, I wouldn't have made it without your help! I'll be performing the maintenance tomorrow I think, I'll also be plugging the robot to my computer for the first time in a while.