Also, MFR Rednet cables don't connect to everything they way they should. In my case I was using a Steve Carts tree farm with a turtle to empty the tree farms inventory. But I only wanted the turtle to empty it out when the cart was on the other side of the tracks. I could not get the turtle to red the rednet cable status. I wound up putting vanilla redstone on top of the rednet cable to so the turtle could sense the signal.
Just like changing colors, but click on the center node itself. You want to change the force mode. Remember to set the colors for the other attachments to a "blank" color (eg one you don't use) to prevent accidental interactions. You can temporarily place blocks around it to get to the color rings, even if you break the block after the color is "saved"