AB PLC interface to a DX200 Controller (Ethernet/IO)

    I haven't done the PLC end on a DX200 controller and was wondering if there is a listing of the IO signals required to start the robot via an AB PLC. I can seem to make sense of the listings they provide in the manuals.

    CIO is dependent on the application of the robot (Handling, welding...). You should have gotten a copy of drawings with the IO structure so you can make your PLC connection list. If you don't have a set of drawings contact Yaskawa. Make sure you know the application and any other add on (I/O cards, external axis...). There should be a warranty ID number on the controller. Yaskawa should be able to look up what they sold from that number and provide drawings.

    Robodoc

    I typically map the following signals from specific I/O to universal I/O, in the Ethernet/IP (or whatever protocol I may be using, DeviceNet, etc.) address space:


    Robot To PLC
    * External Start -- 70010 maps to 20070
    * External Servo On -- 40045 maps to 20071
    * Call Master Job -- 40070 maps to 20072


    PLC to Robot
    * Running -- 50070 maps to 30070
    * Servo On -- 50073 maps to 30071
    * Top Of Master -- 50020 maps to 20073
    * Remote Mode -- 80011 maps to 20074


    The default mapping to/from the 200xx and 300xx addresses will differ by application (general, handling, arc weld, or spot weld).


    I map several other things as well, these are just the bare minimum you will need to start the robot remotely from a PLC.


    You will have to modify the ladder to create these mappings, which is easier said than done if it's your first time doing it. Read the Concurrent I/O manual several times, and the sticky on CIO for beginners in this forum. Also read the manual for your option board, there should be some helpful info on how the I/O gets mapped there as well.


    The one thing for DX200 that isn't clearly explained anywhere I've seen is the new BMOV ladder instruction. Due to the large amount of I/O, Motoman replaced the GSTR/GOUT instructions in the stock ladder file with a single BMOV instruction, which is a block copy. You will have to modify this instruction to eliminate duplicated coils. The instruction's format is:


    BMOV <source start address>, <byte count>, <dest start address>


    Once you have modified and verified the ladder, the next step is to write PLC code to start the robot. The basic sequence I use is:


    1) Verify the robot is in remote mode, and any other start conditions you have, i.e. safeties, robot at home, HMI start button.
    2) Call master job (if required or desired). Wait for the Top Of Master input.
    3) Turn on servos. Wait for the Servo On input. I then wait a half-second before continuing, I have had issues if I don't.
    4) Start the robot, and verify the Running input is on.


    There's more than meets the eye in all this. CIO ladder is the most frustrating, confusing, contrived, cryptic, and most poorly documented piece of the Motoman robot. I keep a "standard-modified" CIO file for each controller and application I use, and load it early in the startup process--usually right after I set up Ethernet/IP, so I don't have to go through the same pain all over again every time I power on a new robot.


    Scott

    Oh, and also search this forum for MLADDER. It's a free program that you can use to view CIO ladder graphically. I use it almost daily. It does not recognize the BMOV instruction, but this hasn't really affected its usefulness.


    Scott

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