KUKA KRC4 RDC Memory is Empty After Power Cycle

    Hey all,

    Ever since we upgraded our KRC2 system to a KRC4 (a little over a year ago) we've been getting an error after power cycle of the unit. The message reads "RDC memory is empty. Should the archive data be written to the RDC memory?"

    Typically we select yes and have no further issues, but one time a technician accidentally hit "No" and we ended up taking extended downtime due to having to remaster our 4-axis robot. We've checked the batteries on the system and did not identify any issues so far. I'm not sure what else could be causing this error and was looking for some insight. Any help is greatly appreciated!


    Thanks,

    Just how, exactly, did you go about 'upgrading' your robot to a KRC4?

    KRC2s and 4s use different RDC cards. On the KRC2s, the RDC card EEPROM is located on the card itself. On the KRC4, it's located on a separate circuit board hidden behind the RDC. If you somehow 'hacked' a KRC4 onto a robot that still has a KRC2 RDC card in the base, that might explain it.

    "RDC memory empty", though... that's an error I've never seen before. It implies that the memory was wiped, not simply corrupted. On older KRC2s, a bad power-down (bad batteries, usually) would result in a loss of Mastering data, but not the serial number or hour meter. What happens if you simply warm- or cold-boot the robot, without actually shutting off the main power?

    Hey guys,

    Panic Mode - I'll get a KRCdiag the next time we get an opportunity to shut the system down again. I do have a spare RDC & EDS, any recommendation on which to try first? Or does it really not matter?

    SkyeFire - We did a full replacement of everything. New RDC, Controller, Cabling, etc. Nothing from the KRC2 is left. I will also try a warm/Cold boot of the robot during the next opportunity and let you know!


    Thanks for the tips!

    Hmm, that is something I'm unsure of. We used an outside company to commission the robot, I know that our group never did the initialization. Would the controller still be able to run without doing so? Would it throw any errors (other than the RDC error we're seeing now) letting us know that it was not done?

    I'll take a look in the safety configuration during the next opportunity we have!

    Hey Guys!

    Sorry for the wait, today is the first maintenance outage we've had since I posted this.

    We just changed out the RDC & EDS on our unit. We then powered it back up, and it prompted us with the same question "RDC memory is empty. Should the archive data be written to the RDC memory?"

    We hit yes as usual and it reconfigured the RDC, but is now telling us we need to remaster all four of our Axis (which it did not do in the past.) Also, this time when I went into the safety configuration screen it prompted us that there was a change. We selected the option for RDC being started for the first time and activated the safety configuration. After a power cycle we were then prompted with the same "RDC memory is empty" message :icon_frown:

    I've contacted the KUKA FOCUS center and still waiting to hear back from them. Any other ideas?

    We checked the batteries out again today and the voltage was good and had no blown fuses anywhere. When we looked at the $ACCU_STATE variable though it displayed #CHARGE_UNKNOWN. Not sure what to make of this yet.

    All,

    After talking with KUKA and getting some available downtime, we finally fixed this issue!

    I had to reformat the EDS and enter in a robot number.


    Just in case anyone else ever needs to do this, here are the instructions to format the EDS.

    -Sign on as EXPERT USER
    -Select Display -> Variable -> Single
    -in the ‘Name’ box, enter "=delete_RDC_content()" (without the quotations)
    -Press REFRESH…..Current status should read #SUCCESS
    -go into SHUTDOWN and select both COLD START and RELOAD FILES
    -Restart the controller
    -You should get the message RDC memory not programmed. Do you want to use the data from archive?
    -Select NO and enter in a 6 digit number for serial number (normally this would be a robot serial number but in our case of just using KMC there is no robot so we could use any number)
    -Perform a COLD START again with RELOAD FILES

    Thanks again for all of your ideas to try!

    -Fyb3r

    messages are displayed in order they appear. you should look at older messages first. there is more to it as shown by scroll bar. you only show the most recent ones.

    also this is a English forum...

    so before you take image, change language to English. then post them here... or i could move your post to forum section Other languages. you will notice that those other forum section are not nearly as active as this one and you will likely be waiting a long time for a reply.

    1) read pinned topic: READ FIRST...

    2) if you have an issue with robot, post question in the correct forum section... do NOT contact me directly

    3) read 1 and 2

    you attached same image twice. oldest messages are still not shown. you need to scroll down.

    in KRC4 architecture, RDC flash is not on the RDC itself. it is on a separate unit called EDS that pugs into RDC. Check if the EDS is connected. if it is or if the ribbon cable is damaged, your robot will need new EDS. in fact there are two of them:

    first one is connected to RDC and keeps track of robot data.

    the second one is inside KRC4 and connected to CCU. this one is keeping track of things like safety IDs but as i recall it was unused on early KSS version (KSS8.2). So if your robot happen to be old enough and running KSS8.2, in an emergency it could be used as a spare part to replace the broken EDS on the robot...


    EDS is bolted to metal chassis. to replace it, power down robot, care fully unplug EDS from the board then remove the RDC board to access EDS.

    1) read pinned topic: READ FIRST...

    2) if you have an issue with robot, post question in the correct forum section... do NOT contact me directly

    3) read 1 and 2

    best regards.

    How about thanks for the information.

    the initial problem was that it did not detect any axis, the rdc card was changed and it already detected the axes but it showed the alarms sent in the images.

    do i have to register the rdc card? the tape with the memory remains the same as the previous rdc card

    Atte: Carlos

    Quote from jcnsanchez

    the rdc card was changed ...

    EDS cable is short and easily damaged if retention clip on the connector was not released.

    EDS stores number of things including robot serial number, machine data, KLI config, mastering data etc.

    and sure enough - there are messages complaining about each of those. so replacement EDS would be on my list, along with initializing it with correct robot data and mastering robot.

    if EDS is not ok (damaged/unplugged) then replacing RDC will not make those messages go away.

    1) read pinned topic: READ FIRST...

    2) if you have an issue with robot, post question in the correct forum section... do NOT contact me directly

    3) read 1 and 2

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