3Com Router 5000 and Router 6000 v2.41Module Guide Chapter 2 Smart Interface Cards2-32.2 Router 1-Port Serial SIC2.2.1 Introduction1-port multiprotocol synchronous/asynchronous serial interface card (Router 1-PortSerial SIC) supports both synchronous and asynchronous operating modes. Itsupports:z Transmission/Receiving and handling of synchronous and asynchronous serialdata streams;z Different operating modes, such as V.24/V.35 and DTE/DCE, depending on theactual applications;z Automatic external cable type detection without the need of manual configuration;z Local loopback and remote loopback, facilitating fault test and location.I. Synchronous and asynchronousIn different operating modes, a synchronous/asynchronous serial interface supportsdifferent signal standards and baud rates and the maximum transmission distance ofthe signals is related to the baud rate setting. For the relationships between cable type,baud rate setting and signal transmission distance, see the following table.Table 2-3 Baud rate and transmission distance of V.24 (RS232)/V.35 cableV.24 (RS232) V.35Baud rate (bps)MaximumtransmissionDistance (m)Baud rate (bps)MaximumtransmissionDistance (m)2400 60 2400 12504800 60 4800 6259600 30 9600 31219200 30 19200 15638400 20 38400 7864000 20 56000 60115200 10 64000 50- - 2048000 30
