Matrix +3 interfaces (CCI-22, FOR-22, TEL-14) cannot work directly with a Matrix +2 frame types, the PIA-32 must be used to translate the audio and digital control signals.
The PIA-32 is a stand-alone, one-rack-space translator that converts Matrix +3 ports to Matrix +2 ports. It allows existing Matrix +2 systems, interfaces and accessories to be used with Matrix +3 systems without modification. Each unit connects six Matrix +2 ports, interfaces, or accessories to the Matrix +3 frame.The PIA-32 translates the different call-signal protocols used by Matrix +3 and +2, allowing trunking between systems. It also enables connections between the Matrix +3 frame and the outputs of existing IMF-1 interface frames, and permits interface ID.  Further, it enables the connection of third-party telephone interfaces and of the Clear-Com AB-100 On-Air Announcer’s Console to Matrix +3 without any modifications.