This module adds pulse and tone dialing functionalities to the XPO-CAT system, requiring an external phone line for testing. It features 18 test points, 20 banana sockets, and LEDs for monitoring internal signals. Additionally, 15 physical and 7 hidden fault switches are included for troubleshooting purposes. A separate DTMF decoder section with RJ11 connectors and LEDs provides further analysis capabilities. While aesthetically integrated with the XPO-CAT MU mold, it doesn’t utilize its top board resources.