Mitel SX-200 Documentation page 476

8.30 If the circuit is programmed as a DTMF trunk circuit, a tone
generator will be inserted as illustrated in Figure 8-3(f). This
results in the digital data signals being translated into DTMF tone
pulses which are then placed on the speech path (not into the trunk
card) and fo&arded to the trunk circuit for outward transmission. The
audio path is isolated back to the console when the DTMF transmis-
sion takes place.
Console Data Updating
The console indicators are refreshed and/or updated continu-
8.31
ously every 100 ms by the firmware. These indicators include
the 7-segment displays for the time-of-day clock, the source and
destination readouts and the calls waiting display, as well as over
8.32 The status of each of these indicators is maintained in the
volatile RAM. Every 100 ms, the processor addresses the RAM
on the console control card and sends it 64 bytes of information for
each of the two consoles. This data is then sent through the DART0
where it is changed from parallel-to-serial data, and along a pair of
wires to the console.
In the console, the information is once again clocked into a
8.33
. .
UART to be transformed into parallel data and stored in a RAM.
At this point, the console's microprocessor takes control and sorts this
input file into the form required to turn on/off the matrix of LEDs and
the console ringer.
D. Power Supplies
8.34 The operation of the SX-100 and SX-200 PBX power supply
arrangements are described in the following paragraphs.
Power Supply, SX-100
8.35 The SX-100 power supply is mounted to the right-hand side of
the SX-100 card file. It is a fully RFI-shielded switching power
supply consisting of the following sections:
AC/DC
DC/DC
Ringing Generator
l
Out-of-Tolerance Detector.
8.36 The AC/DC converter is designed to operate with an input of
115 Vat, 44-64 Hz and produces a controlled output of 53 Vdc.
This 53 Vdc source is supplied to the DC/DC converter where it
generates the following output voltages:
-5
l
Converter
Converter
volts 5 %
5 %
volts
SECTION 9105/91 lo-096-180~WA
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