NTAK792.0 MbPRI c ard Page487 of 544
Option11C and 11C Mini Technical Reference Guide
DCHI special applications connection
The connection between the PRI2 and the on-board D-Channel Handler
Interface card is also available at the MDF connector. The signals confirm to
the EIA RS-422 standard. Connections would not be made to these pins for
normal on-board DCHI operation. They are available for future or special
applications.
Card-LAN interface
A Dual Port UART handles the functions of the serial ports for the Card-LAN
serial link and the echo canceller/test port interface. The echo/test interface is
an asynchronous 4800 bps 8-bit connected to port A of the UART. The card-
LAN interface is an asynchronous 19.2 kbps 9 bit start/stop connected to port
B of the UART.
The connection to the echo canceler/test port is available at the backplane/
MDF connector. The signals at this port conform to the EIA RS-232C.
Clock controller interface
The clock controller circuitry on the NTAK79 is identical to that of the
NTAK20 clock controller.
Note that while several DTI/PRI packs may exist in one system, only one
clock controller may be activated (all other DTI/PRI clock controllers must
be switched off).
Clocking modes
The clock controller can operate in one of two modes: tracking or non-
tracking (also known as free-run).
Table 1 52
Settings for the DCHI dip switch (SW1)
Switch Function On Off
S1-1 En/Dis Enabled Disabled
S1-2 F/W Mode DPNSS DCHI