User's Manual

3-3
Cisco 3200 Series Mobile Access Router Hardware Guide
OL-5816-04
Chapter 3 Serial Mobile Interface Card (SMIC)
SMIC Component Systems
Signals for the SMIC
The Cisco SSB Serial standard supports the following:
• EIA/TIA-232, EIA/TIA-449, EIA-530, EIA-530A, X.21, and V.35 standards in both DTE or DCE
modes.
• Signals (SSB and LED) are provided through the 60-pin multifunction header(s).
The position of the rotary switch determines the port assignments. Although the rotary switch has eight
positions, only position 0, 1, and 2 are supported on the 4-port SMIC and only position 0 and 1 are
supported on the 2-port SMIC.
Table 3-2 provides 4-port SMIC port assignments.
Table 3-3 provides the 2-port SMIC port assignments.
Serial Cable Length
Maximum Cable length depends on a number of factors, including how well the sender and receiver are
implemented regarding rise times, and cable capacitance, inductance and screening. These are all
difficult to quantify, but the primary factor is the data rate. Typically, doubling the data rate halves the
recommended maximum cable length.
The RS-232 specification limits cable length to 15.25 metres (50 feet) at a maximum data rate of
20,000 bps. The Cisco 3200 Series router RS-232 serial interfaces data rate is 115,200 bps and are
limited to a maximum cable length of 2.8 meters (8 feet).
Table 3-2 4-port SMIC Rotary Switch Settings and Port Assignments
Position MIC Slot Port Assignments
0 1 Serial 1/0 Serial 1/1 Serial 1/2 Serial 1/3
1 2 Serial 2/0 Serial 2/1 Serial 2/2 Serial 2/3
2 3 Serial 3/0 Serial 3/1 Serial 3/2 Serial 3/3
Table 3-3 2-port SMIC Rotary Switch Settings and Port Assignments
Position MIC Slot Port Assignments
0 1 Serial 1/0 Serial 1/1
1 2 Serial 2/0 Serial 2/1