Datasheet

Connecting Cisco CEoIP Network Modules to the Network

Connecting 4-Port Serial Interface Network Modules to the Network

Connecting Cisco CEoIP Network Modules to the Network

The following control signals are part of the extended set, in addition to the basic set listed above, and

are used on Cisco Extended 12-in-1 cables:

• Remote Loop (RL)

• Test Mode (TM)

• Ring Indicator (RI)

Note Control signal support depends on the interface type. Not all of the control signals listed above are

supported by every interface type.

Note The control signal names used in this document are the names commonly used in the industry for

RS-232. Other interface types may use other names for the equivalent control signals.

The 4-port serial interface network module (NM-CEM-4SER) supports both Cisco 12-in-1 interface

cables and Cisco Extended 12-in-1 interface cables with user-defined end-connectors permitting

connection to either DTE or DCE interfaces.

Interfaces and DTE or DCE modes are defined by the type of cable connected to the network module.

Tip Use the Cisco 12-in-1 cable for X.21 interfaces. The X.21 interface connector does not require an

additional DIN connector.

For information on using Cisco 12-in-1 cables with the 4-port serial interface network module, see

Table 3. Figure 4 illustrates how to connect the Cisco 12-in-1 cable to the network module.

For information on using Cisco Extended 12-in-1 cables with the 4-port serial interface network module,

see Table 4. Figure 5 illustrates how to connect the Cisco Extended 12-in-1 cable to the network module.

All serial interface types are available in DTE or DCE format: DTE requires a plug connector at the

customer premises equipment (CPE) end, and DCE requires a receptacle connector at the CPE end.

Serial Interface Data Rates and Distance Limitations

All serial signals are subject to distance limits, beyond which the signal degrades significantly or is

completely lost. Generally, the slower the data rate, the greater the distance the signal can travel.

Table 2 lists maximum recommended speeds and distances for each serial interface type. If you

understand and compensate for potential electrical problems, you may get good results at speeds and

distances greater than those listed. For instance, the recommended maximum rate for V.35 is 2 Mbps,

but 4 Mbps is commonly used.

Table 2 Maximum Recommended Speeds and Distances for Each Serial Interface Type

EIA/TIA-232 Distance EIA/TIA-449, -530, -530A, V.35, X.21 Distance

Data Rate, bps Feet Meters Feet Meters

2400 200 60 4100 1250

4800 100 30 2050 625

9600 50 15 1025 312