KRC4 Compact X11 and X55 - once again

  • Hello guys,


    I have already spent a few hours going through topics related to safety over X11 on KRC4 controllers. I do have to create some eplans, as well as to choose proper higher level safety controller configuration, but still need to clarify some questions... What's more, I will not have acces to the controller in next 2 weeks, so I can't test anything by myself :icon_neutral:


    Controller is KRC4 Compact type with X11 safety connector and Beckhoff I/Os. I have got paper-version eplan but it is covering not all interfaces :hmmm:


    1. X55 Connector


      • Ok, the only thing that I'm sure is that on pins 7 & 8 there is 24VDC output, which can be bridged on other pins to use internal 24VDC supply, but....

      • what exactly is "Infeed Terminal" on pins 1 & 2?

      • EtherCAT Bridge - is it just 24V supply for internal Beckhoff I/Os? pins 3 & 4

      • the last one - Bus Coupler - no idea what it is for?


    2. X11 Connector


      • Do I need to make any X55 jumpers to get X11 interface working properly or not? In other words, is the X11 powered internally only, or is it possible to use external voltage on X11 (i.e. the same that powers external safety controller) ?

      • According to X11 pinout to control KUKA External E-Stop one possibility is to use safety relay between pins 1&2 and 10&11. Is it possible to control this E-Stop without relay, just with safe pnp outputs from safety controller (pilz or sick) - such a solution would require external voltage supply for X11, I guess..?

      • I know that wiring External E-Stop and User Safety is essential. But do I need to wire "Acknowledge Operator Safety" or this acknowledgement can be made with $CONF_MESS?



    I hope, that you guys will help me with my questions :help:


    Best regards!

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  • X55 pins 7/8 are internal power supply, other pins 1/2 or 3/4 or 5/6 are different loads.
    X12 is option used to provide some I/O on the controller itself.



    in the past X55 pins 5/6 was used to power EtherCat I/O based on Beckhoff I/O modules.
    nowdays I/O module is IOB card and for some odd reason, it is powered from X55 pins 1/2 instead of 5/6.



    If you ask me, i would use multiconductor cable and wire all X55 pins to a terminal strip where it is convenient to jumper anything you like any way you like. This is also practical to provide biasing for I/O on X12.



    X11 has nothing to do with X55. X55 is used to loop power to different periphery not safety circuit.



    According to controller documentation, safety inputs are meant for floating contacts (also known as potential-free or "dry" contacts).



    You can configure in safety configuration if operator safety acknowledgement is done at X11 or not.
    Robotics safety standards require safety to be acknowledged manually and therefore it must be part of safety circuit but if there is external safety controller that has acknowledge button, you don't have to duplicate that by adding another button on X11.



    $CONF_MESS is only able to acknowledge messages in EXT mode.

    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

  • Hi, what would be the best way to connect the cable to the X55 socket of the KRC4?


    Do you know whether it is possible to purchase a cable with the correct plug already terminated onto the cable, or would I need to purchase the plug and cable and terminate it on my own?

  • The best way is subjective... For me the best way is to do as intended:

    a) get mating connector from KUKA (not sure about the cost), proper crimper for this (about $400) and pin extractor (about $100). pin extractor is used to take contacts out (if mistake is made - contact is damaged or in wrong position)

    b) set up crimper correctly for used contact and wire size,

    c) prepare cable with sufficient number of conductors (i prefer to wire each contact)

    d) crimp them correctly, meaning no loose strands, no cut strands, all strands need to be inside contact and reach inspection hole, wire insulation need to be against the contact.

    e) perform pull test on each contact. if the wire comes off, or wire gets broken, crimper is not set correctly and work must be repeated.

    f) insert contacts into right positions and complete connector assembly. this need to be done once but must be correct, specially if you don't have the proper tools yourself and had to borough them for example. if you have used cables with wire for each contact, it is easier to adapt later on if needed (even if you no longer have access to crimper or pin extractor) since the other side of the cable is supposed to be much easier to access (see next step). people often fall into trap and place KUKA supplied jumpers and later they realize "oh crap, i need to use IO so must get those contacts removed and connect cable"

    g) terminate other end of the cable. either at some other connector or where possible at DIN rail terminal strip, place jumpers at the terminal strip as needed to connect positive and negative terminals any way you need.


    alternatively one can get tools from one of alternative brands that claim compatibility. this may be slightly cheaper and perhaps include case etc.


    another option is to solder wires to contacts. this is doable but need to be done carefully as any excess solder will prevent assembly etc.

    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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