3Com 3C13701 3C13751 3C13755 3C13759 3C13840 3C13880 Network Router User Manual


 
3Com Router 5000 and Router 6000 v2.41
Module Guide
Chapter 2 Smart Interface Cards
2-3
2.2 Router 1-Port Serial SIC
2.2.1 Introduction
1-port multiprotocol synchronous/asynchronous serial interface card (Router 1-Port
Serial SIC) supports both synchronous and asynchronous operating modes. It
supports:
z Transmission/Receiving and handling of synchronous and asynchronous serial
data streams;
z Different operating modes, such as V.24/V.35 and DTE/DCE, depending on the
actual 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 asynchronous
In different operating modes, a synchronous/asynchronous serial interface supports
different signal standards and baud rates and the maximum transmission distance of
the 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 cable
V.24 (RS232) V.35
Baud rate (bps)
Maximum
transmission
Distance (m)
Baud rate (bps)
Maximum
transmission
Distance (m)
2400 60 2400 1250
4800 60 4800 625
9600 30 9600 312
19200 30 19200 156
38400 20 38400 78
64000 20 56000 60
115200 10 64000 50
- - 2048000 30