363-206-295
Technical Specifications
10-26
Issue 1
December 1997
Operations Interfaces (OI)
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0
This section presents the operations interfaces that are required to support
technician access to the system and allow alarms and status information
generated by the system to be reported. The local operations interfaces include
the CIT interface, the user panel, and the equipment indicators. DDM-2000 OC-12
Multiplexers support office alarms, user-definable miscellaneous discretes, and
TL1/X.25.
Craft Interface Terminal (CIT)
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The system provides two EIA-232-D compatible CIT interfaces—a front access
interface, configured as a DCE, and a rear access CIT interface, configured as a
DTE—to allow a permanent modem connection without requiring a null modem. A
null modem is required to connect an ASCII terminal to the DTE interface or a
modem to the DCE interface. The CIT interfaces provide data rates of 300, 1200,
2400, 4800, 9600, and 19200 baud.
Both CIT interfaces operate full duplex using 1 start bit, 8 data bits, and 1 stop bit.
Table 10-15 describes the pins supported on the CIT interfaces:
Table 10-15. CIT Interface Pin Connection
A CIT is recommended for installation, maintenance, and administrative activities.
A PC is required for software download and to run CPro-2000 software. The
DDM-2000 OC-12 Multiplexer CIT port (mounted on the user panel) is a standard
EIA-232-D (supersedes RS-232C specification) interface configured as DCE for
direct connection to a CIT. The CIT port will support rates of 300, 1200, 2400,
4800, 9600, and 19200 baud and should be compatible with most
ANSI 3.64
EIA-232-D Pin
Front Access CIT (DCE)
Rear Access CIT (DTE)
Pin 2—Circuit BA
Transmitted Data
carries data from
terminal to DDM-2000
carries data from DDM-2000
to modem or terminal
Pin 3—Circuit BB
Received Data
carries data from
DDM-2000 to terminal
carries data from modem or
terminal to DDM-2000
Pin 7—Circuit AB
Signal Ground
signal ground
signal ground
Pin 8—Circuit CF
Received Line
Signal Detector
not used
indicates to DDM-2000 that
modem or terminal is connected
Pin 20—CIrcuit CD
DTE Ready
indicates to DDM-2000
that modem or terminal
is connected
indicates to modem or terminal that
DDM-2000 is connected (always ON
when SYSCTL is powered)