Before You Start..

Before connecting the ACE PLC to the PC

  1. Install vBuilder
  2. Run vBuilder
  3. Plug the ACE PLC

PLC may be powered :

  • via USB (except ACE with analog outputs)
  • or 5V on its power plug.
    • You can plug both at the same time.

Before wirring the PLC outputs

Enable the PLC to start up the program after power-up cycle

  • In vBuilder:
    1. Upload the program  
    2. Run the program 

Now the ACE PLC will start program on power-up. Never run Debug mode, then leave the PLC in production.

How to check the connection with my ACE PLC, my PC and vBuilder ?

  • If…
    • The ACE PLC is not see with vBuilder or Windows.
    • No USB  sign bottom right-hand corner of your vBuilder screen.
    • In Setup Hardware, the button  doesn’t work.


  • Check if you see the COM port in vBuilder with this tool:
  • Check in your Windows device manager (devmgmt.msc) if you see VelocioComm
  • if not, try this :
    • Plug and unplug USB cable, and have a look to the Device Manager Windows.
    • If the list refreshes as you plug it in/unplug it, it sees something.
    • If it is an unknown device, then it’s probably that you needs to install the driver:
      1. Uninstall vBuilder
      2. Restart your PC (advisable)
      3. Install vBuilder
      4. RUN vBuilder
      5. Plug PLC
    • If nothing happens, check if the led of the PLC blinks. If not, check the power supply or maybe the power of your USB port.
    • Try to change the USB cable (Some USB cable can work with some devices, but not with all devices – due to the wire diameters of the USB cable)
    • Try on another PC