Actor is a software module for Trunk Navigator (Art.-Nr. 1080005, not included); the Actor option enables Trunk Navigator to interface with 3rd-party Intercom systems via RS-485; an external RS-485 converter is necessary for interfacing with 3rd-party Intercom; this device is not included; Riedel recommends the Advantech EKI-1521, EKI-1522 or EKI-1524 for this purpose; compatible with Trunkmaster 8.7.1.