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DTI installation
553-2811-200
Standard 6.0
December 1994
Note:
A system cannot use both the QPC471 and the QPC775. A system
can mix Clock Controller vintages A through G. Vintage H Clock
Controllers can be used only with another vintage H Clock Controller.
DTI interfaces
The DTI card provides a connection to the DS-1 channel interface directly
through an office repeater or through an Echo Canceller.
In the U.S.A., FCC Part 68 regulations require Network Channel Terminating
Equipment (for example, the NTQRY551 Channel Service Unit) installed at
each connection point of a private system to a registered common carrier
trunk.
Echo Cancellers are required only if satellite transmission is used. The DTI
card provides both a T1 line interface and a control interface to link with a
signal format compatible with EIA standard RS-232-C. Both the DTI and the
Echo Canceller act as Data Terminal Equipment (DTE). The Echo
Canceller’s control protocol must conform with that of the Tellabs
Model 251.
QPC472 DTI specifications
The QPC472 DTI only requires power and ground from the backplane. Power
requirements are as follows:
+5 volts at 3 amperes
+12 volts at 50 milliamperes
-12 volts at 50 milliamperes
