Hypercom IEN 1000, Справочник по аппаратуре

Страница: 73 / 198

PORT PROCESSORS/MODULES
940043-002 INTEGRATED ENTERPRISE NETWORK 3-27
DTC11-E1
The DTC11 port processor (Part #030012-003) is a single CPU that interfaces with a DSX-1
E1 (DTC11-E1 port processor) line to the node PCM bus. The DTC11-E1 port processor
contains all circuitry necessary to convert the 4-wire, self-clocked AMI T1 signal to the
synchronous TDM PCM highway. The DTC11-E1 port processor contains a high-
performance Digital Phase Locked Loop (DPLL) that synchronizes the internal 2.04 and 4.08
MHz PCM highway clocks to the incoming E1 signal.
The reverse is true when the DTC1-E11 port processor is used to provide master clocking.
That is, the E1 transmit clock is locked to the PCM highway clock. In addition, the DTC11-
E1 port processor contains a 512-channel digital space-time switch used for multiplexing
and channel control. The DTC11-E1 port processor supports ISDN PRI when combined with
CID61 port processor for D and B channel termination.
DTC11-LHO
The DTC11-LHO port processor (Part #030012-002) is a long haul receiver that is typically
designed to fully restore a received signal after transmission though a cable with
attenuation of either 0 to 26 dB, or 0 to 36 dB. The smaller range allows for increased
noise margin in shorter loop operations. The DTC11-LHO port processor standard features
are identical to the DSX11 port processor standard features except for the long haul
transceiver receiver capability.
Since there is no DSX-1 reference point in the long haul interface, all pulse amplitudes are
referenced at the transmitter output. The long haul transmitter does not have any provision
to boost the signal to provide a constant pulse amplitude at the non-existent DSX-1.
However, there is a provision to attenuate the output signal in 7.5 dB steps up to 22.5 dB.
This attenuation is required by FCC Part 68 Regulations and is required for short line
lengths to prevent far-end crosstalk.