Nortel Networks Option 11C User Manual
NTAK93 D-channel handler interface
Page 515 of 544
Faceplate LEDs
NTAK09 1.5 Mb PRI and NTBK50 2.0 MB PRI cards
LEDs are located on the faceplate of the NTAK09 and NTBK50 cards. The
DCH LED is dual-color (red and green), with states represented as follows:
DCH LED is dual-color (red and green), with states represented as follows:
Power consumption
Power consumption is +5V at 750mA; +12V at 5mA; and -12V at 5mA.
Functional description
The main functional blocks of the NTAK93 architecture include the
following.
following.
Microprocessors
One microprocessor handles data transfer between each pair of serial ports
and software, reports the status of each port and takes commands from
software to control the activities of the ports. The microprocessors also do
some of D-channel data processing in DCHI mode.
and software, reports the status of each port and takes commands from
software to control the activities of the ports. The microprocessors also do
some of D-channel data processing in DCHI mode.
DMA controller
A Z80A-DMA chip controls the data transfer between local RAM memory
and communication ports. Note that the DMA channels will only be used in
the receive direction (from line to CPU), not in the transmit direction.
and communication ports. Note that the DMA channels will only be used in
the receive direction (from line to CPU), not in the transmit direction.
Random Access Memory (RAM)
A total of 32K bytes of RAM space for each pair of ports is used as the
communication buffer and firmware data storage.
communication buffer and firmware data storage.
Table 160
Faceplate LEDs
Faceplate LEDs
State
Definition
On (Red)
NTAK93 is equipped and disabled.
On (Green)
NTAK93 is equipped and enabled, but not necessarily established.
Off
NTAK93 is not equipped.