Nortel Networks Circuit Card Manuale Utente

 NTAK79 2.0 Mb PRI card

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receive clock output 

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transmit clock output 

The receive and transmit clocks have slightly different bit rates from each 
other, as determined by the transmit and receive carrier clocks.

The NTAK79 has an onboard D-Channel Handler Interface (DCHI). It is the 
equivalent to a single port of an NTAK02 SDI/DCH pack. This enables for a 
completely operational ISDN PRA link with clock synchronization and 
D-channel on a single circuit card.

The onboard D-channel has one status LED on the NTAK79 faceplate to 
indicate enabled/disabled states. See Table 239 on 

The on-board DCHI can be operated in two separate modes as defined by an 
on-board dip switch. It can operate in a standard DCHI mode common to 
most ISDN standard countries. The U.K. specific mode that uses the DPNSS 
format is not supported at this time.

The connection between the PRI2 and the on-board D-channel Handler 
Interface card is also available at the MDF connector. Connections are made 
to these pins for normal on-board DCHI operation. They can also be used for 
future or special applications.

The signals conform to the EIA RS-422 standard.

S1-1

En/Dis

Enabled

Disabled

S1-2

F/W Mode

DPNSS (not 

supported at 

this time)

DCHI