I/O and Cabling Considerations
3.3
Telco Cabling Options
The model 721 16-port I/O module and model 724 24-port I/O module can be used with a variety
of cabling options that are designed for easy cable connections. The cabling options available
from Xyplex include:
• Extension cables
• Distribution panels
• Splitters
• Octopus cables
• Punch-down blocks
• Modular (MODtap™) cabling
• DECconnect™ cabling
Standard cabling items available from Xyplex allow you to connect to any serial device that
uses a male or female DB-25 connector.
Xyplex also supplies DECconnect-compatible crossover cables and modular adaptors for use
with the 20-port I/O modules. These cables are described later in this chapter.
3.3.1
Rear Panel Connection (Telco)
The Model 721 I/O module has two 50-pin female Telco/Amphenol connectors with bail locks,
as shown in Figure 3-10. The Model 724 I/O module is similar to the Model 721, but has has
three 50-pin female Telco/Amphenol connectors with bail locks. The bail locks swing in
toward the male connector and latch to secure the connection. Standard Xyplex cables use
connectors with the bail locks.
Figure 3-10. Sixteen-Port I/O Module, With 50-Pin Telco Connectors.
Table 3-1 lists the Telco 50-pin connector pin assignments for the Terminal Server 720
sixteen-port I/O module. Typically, an extension cable, with either a straight-out or bottom-
entry male connector is mated to the Telco connector (section 3.3.2).
☞
The model 721 and 724 I/O modules do not support hardware flow control.
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