How Do Third Party Vision Systems Communicate with A Fanuc Controller?

  • Hey Guys,


    I've been searching for an answer to a question for about a week now. I am curious how a third-party vision system sends offsets to a Fanuc robot. I read that a lot of them just send the offsets to a Group Input, but that seems a bit inefficient since from what I can tell you would have to convert the binary data into a real number that can be stored in a register.


    Is there another way to write an offset from a vision system directly to a register?


    My company is using a VFix System from Liberty Reach to a 30ib Controller.


    Thanks Guys!

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  • You would need to ask that vendor which communication protocol they use. Fanuc robots can communicate in a number of different protocols. Generally you have to purchase them as an option.


    If you have a comm option then you would normally send real numbers directly to robot registers.

  • Okay, that makes sense now. It seems like the answer I'm getting is that you can pay for the more direct options, but the Group Input is what comes standard with the Robot Controller.

  • Correct, using Group inputs and outputs is standard. As HawkME suggested, for the communication with the vision system you should contact Liberty Reach.


    They can tell you which options are required on the robot side. They normally also provide some interfaces (at least for the most common robot manufacturers) for easy communication and integration of the vision system.

    • Helpful

    I've worked with the liberty reach system before (even wrote a driver for them for Abbs). Typically they communicate with the robot using a karel program, and user socket messaging. Other options are to have the PLC communicate with the liberty reach system, and then pass the data to robot via explicit messaging if Rockwell, or some other method if not Rockwell.

    Check out the Fanuc position converter I wrote here!

  • Robots come with GI/GO standard, but what those GI/GOs are mapped to is completely situational. Generally, any standard industrial FieldBus (DeviceNet, Ethernet/IP, ProfiNet, etc) has a Fanuc driver (paid option, mind!) that makes it simple to connect a particular GI/GO to a particular same-sized group of bits on that FieldBus driver. Once mapped, the GIs just update automatically every communication cycle (6ms?), and any value written to a GO gets sent automatically every comm cycle. There is no programming required to send/receive data, the driver handles it all transparently.


    The majority of industrial vision systems support one, or more, of these FieldBus standards.


    Serial and Socket Messaging are different -- they bypass the GI/GO structure entirely, using a different driver stack, and require explicit programming to send/receive data: open a channel, send data, wait for data to come back, close the channel. Often, as with Liberty Reach, this is handled by an endlessly-looping background task of some sort, so as to remove that burden from the programmer who just wants to use the vision system, but sometimes you'll need to write your own vision communications -- depends on what you buy.

  • Correct, using Group inputs and outputs is standard. As HawkME suggested, for the communication with the vision system you should contact Liberty Reach.


    They can tell you which options are required on the robot side. They normally also provide some interfaces (at least for the most common robot manufacturers) for easy communication and integration of the vision system.

    Yes, I just reached out to Liberty Reach and they said that they'll email me a bunch of information on the subject.

    The specifics became really complicated really quickly.

  • Yes, I just reached out to Liberty Reach and they said that they'll email me a bunch of information on the subject.

    The specifics became really complicated really quickly.

    Well, LR provides a software package to install in Fanucs that takes care of all this. There is a list of options your Fanuc has to have to support the LR software, though.


    The way LR's Fanuc package works, certain Registers are dedicated to values going out to the vision system, and other Registers are dedicated to values coming back the other way. Certain PRs are dedicated to certain values, as well.

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