No announcement yet.

Continuation Coil

  • Filter
  • Time
  • Show
Clear All
new posts

  • Continuation Coil

    I am working on a project to replace a GE Fanuc PLC with a DL205. Part of this involves rewriting the versapro ladder logic from the fanuc into direct soft 5 to put on the DL205. In the versapro code there is a coil that looks like --(+)--l . It is called a continuation coil and here is the explanation I found for it:

    "Continuation coil. If any left-to-right path of instructions passes power,
    the next continuation contact is turned on. If there is no continuous
    left-to-right path of instructions passing power, the next continuation
    contact is turned off."

    I do not understand what this coil does and it appears that there is no equivalent in direct soft. Is anyone familar with this type of coil? Is there a way I can emulate this coil in direct soft?

    More Details:

    The PLC runs a wax molding machine. A basic explanation of how they work is that the operator pushes a die under a large hydraulic press. The press then presses down on the die and a nozzle extends out to an opening in the die. The nozzle then ejects molten wax into the die from a tank of wax attached to the machine. Once the the wax fills the die and has been given a few seconds to harden the nozzle contracts and the press opens to allow the operator to reach in and take the die. The operator removes the new wax part from the die and pushes the die back under the press for the cycle to start over.

    Attached is a screenshot of the part of the code containing the continuation coil.

    Thanks for your help!
    Attached Files

  • #2
    I have no clue, but it appears to be a "Temp Bit" that gets used as an OUT coil "place holder" for a bunch of input logic, then immediately used as a contact (possibly in multiple rungs as a contact needing this identical bit state), then re-used as an OUT coil "place holder" for ANOTHER bunch of input logic, then immediately used as a contact, etc.

    I call it my "Temp Bit" where I did not want to burn a C for "intermediate" or possibly "long" rungs that needed to be divided across 2 or more rungs.

    But, I have no idea/clue. That I do know
    There are 10 kinds of people in this world, those who know binary, and those who do not.


    • #3
      franji1's assessment is correct. It was part of the original instruction set for the 90 series. Back then the software allowed a maximum of ten elements wide, nine contacts and a coil. GE's current software imposes no such restrictions on the number of elements, so there is no longer any need for it. When you convert to the AD PLC, you can combine the two rungs into one, omitting the continuation coil and the continuation contact that starts the second rung.


      • #4
        That makes sense, thanks for the help!