Specifications

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Cisco IGX 8400 Series Provisioning Guide, Release 9.3.3 and Later Releases
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Chapter 2 Cisco IGX 8400 Series Cards
Low-Speed Data Module
Low-Speed Data Module
Table 2-48 shows the front and back cards supported for the low-speed data module (LDM).
The LDM consists of an LDM front card and a low-speed data interface (LDI) back card. There are two
LDI variants, depending on the desired number of ports (see Table 2-50).
LDM Front Card
The LDM card is a low-speed data module for use on EIA/TIA-232 ports with data rates up to 56 bps
(4-port back card) or 19.2 kbps (8-port back card), where the higher speeds of an HDM are unnecessary.
The low-speed data module (LDM) front card supports up to eight synchronous data ports. Each port can
be independently configured for DTE or DCE mode, baud rate, and other parameters.
The LDM front card has the following features:
• Performs cell adaptation of customer data and EIA control leads
• Supports normal and looped clocking
• Provides loopback capabilities, testing and diagnostics
The LDM front card can reside in any empty front slot and requires an LDI back card.
The faceplate of the LDM front card has LEDs and buttons for loopback control and signal monitoring.
Figure 2-39 shows and Table 2-49 lists these LEDs and buttons. The buttons are for loopback testing
and scrolling through the data ports to obtain a snapshot of selected port conditions (indicated by port,
port under test, loopback, and communication line status lights).
Table 2-48 Low-Speed Data Module Front and Back Cards
Front Card Back Cards
LDM LDI 4
LDI 8