PLC , BGLogic , or both?

  • Hello,

    I'm wanting to start a program back up from current position if there's been a machine fault such as light curtain interruption. The PLC controls a headstock and tailstock servo axis while the teach pendant controls the fanuc arc mate robot. I cannot start the program back up in auto or T1/T2. I'm curious if this is something I can do with a background logic program or if I would have to add to PLC code. Any thoughts??


  • HawkME the program is being started with the panel view. There's a safety reset/cycle start touch sensor that is swiped. Based on the part number inputed into the HMI it will call up a weld program on the teach pendant where the pass points are taught and weld procedures are inputed. Then it will call up a weldmain 1,2,3,4, or 5 on the pendant based on how many passes. The weldmain program calculates the rotational speed required of tailstock/headstock and starts weld along with a few I/O.
    bidzej - I haven't seen any hold signal errors. I mainly want to give the ability to the operators to hit start again if they break the light curtain/ run out of weld wire so I'm not getting called out everytime. Also reduce rework amount.

  • Is this an Allen Bradley Panelview? Do you know if the HMI is directly communicating with the robot or if the PLC is?

    If you have the PLC or HMI communicating with the robot then you just need to use the UOP signals to reset and start again. UI[5] for reset, and UI[6] for start. The start signal will resume the program from where it left off as long as you have not aborted the program. If you have aborted then UI[6] will either do nothing or start the program again depending on your system config settings. I always set it so that UI[6] Start is for Continue only, so it can only resume a paused program where it left off and not start a new program.

    I am also curious to what program select and start method you are using. You can find out by going to Menu>Setup>Prog Select. and viewing the first 2 items.

  • HawkME - It is an Allen Bradley Panel View. Im assuming the HMI is directly communicating with the robot but not positive. The HMI is where I input pass information for the weld robot such as how many passes and rotational speed. I also use the HMI to control or calibrate the headstock and tailstock axis along with several other air actuated functions.
    The program select mode is PNS
    Production start method is UOP

  • Sean, It is more common that to have the PLC communicating with the Robot. I would check the PLC code first and see if you can find the robot. I take it that the original PLC programmer is not available to make this change or talk to?

    You will need to find out if the communication is hardwired I/O or a protocol such as Ethernet/IP. If it is Ethernet/IP you will see an Ethernet module in the PLC code and Ethernet/IP on the Robot's IO menu.

  • Ok. I was afraid it would be PLC code. I've never messed with any of that. We've never had a PLC programmer employed here. I could call the OEM, but it's not a high priority item. I was looking for continuous improvement ideas to put in my yearly review, and thought this would be a quick win if it was just a few lines of logic in a TP program. That I could definitely do. :( Thanks for the help HawkME!

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account
Sign up for a new account in our community. It's easy!
Register a new account
Sign in
Already have an account? Sign in here.
Sign in Now