Hello again friends.
I'd like some help with this one. I have an R-30iA controller that has no physical robot I/O. Instead, I'm using an Allen-Bradley MicroLogix 1400 to control ALL my I/O (including robot I/O). I have Fanuc Ethernet adapter installed, configured and have mapped out all my I/O correctly. I'm using the robot's UOP I/O (for selecting programs through PNS signals, using an external button for the fault reset, etc.).
What I've noticed is that if I lose communication with the PLC (MicroLogix), all my I/O remain in the state that they were when I lost communication. For example, UI[3] is connected to my safety fence. The signal needs to be off (when the fence is opened) to stop the robot. But when I disconnect the Ethernet cable from the PLC (to simulate a loss of communication), the UI[3] input signal remains on.
My question: Is there a way to configure the robot I/O to return to their normal states (OFF) whenever I lose communication with the PLC?
I understand that using the UI[3] signal as the safety fence interlock is risky because it's a digital signal. But when I considered using the fence interlock on the front panel of the robot controller I realized that whenever the fence interlock was interrupted, it wasn't resettable by just pushing the RESET button. It actually required a series of specific functions to perform before it could be reset (i.e. go to the alarm screen, pushing a physical e-stop button before pressing the res_ch1, etc.). The robot cell will frequently have the operator open the fence interlock after the robot process is complete to remove product and set up the next piece for the operation. So using the fence interlock on the front panel becomes too cumbersome and time consuming just to reset it. Using the SFSPD UI[3] signal is much more convenient.
Unless there is an easier way to reset the front panel fence interlock (with just a push of the reset button alone), I'd rather use the SFSPD UI[3] signal. But I want this (and all other I/O signals) to return to their normally OFF states when communication to the PLC is lost.
I appreciate any help.
Thanks!