http://www.marconi-securesystems.com/products/products-lector.htm The device features a 'RED s bus' allowing it to interface with any data equipment on the crypto input side without additional ISDN interfacing equipment. Data and voice calls can be made via the Red-S-Bus. Calls are established via the terminal equipment connected to the LECTOR Red-S-Bus. Generally, the user is not required to operate any of the LECTOR manual controls when making or receiving Red-S-Bus calls, Red-S-Bus calls require the use of a STK or SuperSTK and entry of a PIN. The S-Bus standard (1.420) allows a LECTOR to have up to eight terminal equipments connected to the Red-S-Bus port. However, it is suggested that no more than four terminal equipments are connected to a LECTOR to reduce the possibility of terminal equipment access problems. Click here for the .pdf datasheet (609kbytes)