safety circuit

  • I am creating a robot cell around a fanuc R-2000iA 165Ew robot with an R-J3iB controller, the robot is attending a spinning machine which operates like a lathe. Iv bought a coded magnet for the door interlock and have bought a safety relay to work with this safety switch. I have also bought two emergency stop buttons to be used externally as well. I was wondering how do I connect these to the controller. I know it has to go to the safety circuit on the back of the door but im not sure as to which pins I should connect to. Also can the emergency stop buttons be connected directly to the robot or do they need run through a safety relay as well. :help:

  • 1. You will be using two separate safety circuits within the robot, Fence for your door interlock, and Ext E-Stop for E-Stop buttons. The difference between the two is that the external e-stop circuit is always active, while the Fence circuit is bypassed in Teach Mode. This allows you to enter the cell and move the robot via the teach pendant when the robot is in Teach Mode. Wiring a door into the Ext E-Stop circuit would prevent you from ever moving the robot with the door open. Wiring an E-Stop into the Fence circuit would probably be a major safety violation, as that E-Stop would not stop motion if the robot were in teach mode.

    2. On the inside door of the robot controller cabinet is a pin diagram for the E-Stop board. The E-Stop board has two blocks of pin slots, TBOP13 and TBOP14. TBOP13 EAS is your fence circuit, TBOP14 ESPB is the Ext. E-Stop circuit. Each of these circuits has four pin slots in two pairs. These are jumpered out by default. You will remove the jumper to install your own safety devices.

    3. A note on the two pairs. Safety devices are dual channel, with two redundant circuits. This means that two independent circuits must fail simultaneously for the robot to mistakenly enter an unsafe state. This is the difference between any normal circuit and a safety rated circuit, as the likelihood of dangerous failure is much much less. It is a major safety issue to just split a single signal in two to complete the safety circuit.

    4. All of this is based on the R-30iB (A Cabinet) and may not translate to your device. It is best to find the electrical manual for your controller and check out its connections section.

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