Drip feed on a Fanuc 6mb

Hello All,
I know its been asked a hundred times and I have read all the threads I can find on the topic, but I still cant figure out the drip feeding of my machine. I have a Fanuc 6mb control. I know the previous owner drip fed it. I have purchased a Mini DNC and it sends small programs fine, but will not drip feed. I don't fully understand the pram G127.5 that has been talked about. If I put my machine selector switch in tape, send the file from the DNC and press cycle start the button lights up and stays lit up, but nothing happens. I feel like a setting in the machine needs turned on but don't know where to start.

Thank you for any help you can provide!
Bill Wolkan