I have a new customer that has a IWATSU system. I meant to get the model number and have misplaced it. I know it is digital and I want to to say is AVIX but an older or first edition. They want to add music on hold to system and upone looking at the cards in slots I did not notice any MOH port. Does this have pins on the 25 pair block or does it take special card and or programming. Thanks,