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,

The MOH port is on the CPU. It is a mod jack. You need to put a line cord between the CPU and a jack. Then short out the pins and hook it up to a source. If it set for external MOH you will hear it. If it is set for internal MOH you will need to change it in Class 4.

Just wanted to add that it is pins 4 & 5 for backround music, and pins 3 & 6 for MOH. Of course, assuming that it is an VS or Adix