Mitel Sx 50 Dpabx Instructions Guide

Engineering Information 
Output Signaling Parameters 
4.3 
The SX-50 system provides make/break ratios of 60/40 and 66/33 for outpulsing on 
trunks. Table 4-3 lists the Dial Pulse Output characteristics. Table 4-4 lists the DTMF 
Tone limits. 
Table 4-3 Dial Pulse Output Characteristics 
Parameter 
Pulse Rate 
Percent Break Ratio 
Interdigit Time 8+11 pps 
58 - 64% 
700 - 900 ms Value _ I 
Table 4-4 DTMF Tone Limits 
Parameter 
Frequency Deviation 
+l% maximum Value 
Signal Duration 
Interdigit Time...

Signaling and Supervision 
provide all the supervisory and dial-pulse signaling required between Central Offices; 
the audio leads are used for DTMF signaling and audio communications. 
Terminating Conditions 
4.5 
The SX-50 system provides the following-line and trunk parameters: 
Station Loop - ONS : The loop resistance, including the set, must be less than 600 
ohms. The ONS Line Card provides a constant current of 25 mA when the set is 
off-hook. Maximum station loop length depends on the gauge of...

Engineering information 
loop Lengths 
Table 4-5 Station Loop Length vs Wire Gauge (ONS Line Card) 
Wire Gauge 
19 
20 
22 
24 
26 
Mix. Station Loop Length 
9,163 m (30,000 feet) 
7,317 m (24,000 feet) 
4,576 m (15,000 feet) 
2,896 m (9,500 feet) _ 
1,829 m (6,000 feet) 
Table 4-6 Station Loop Length vs Wire Gauge (OPS Line Card) 
I Wire Gauge 
I Max. Station Loop Length 
I 
19 37.5 Km (122,900 feet) 
20 29.6 Km (97,100 feet) 
22 18.5 Km (60,700 feet) 
24 11.5 Km (37,800 feet) 
26 7.2 Km (23,700 feet)...

Signaling and Supervision 
Ringing Generator 
4.6 The ringing generator can ring nine circuits simultaneously. However, 
time-division-multiplexing of the ringing signal actually allows 27 circuits to be in the 
ringing state at any time. A maximum of five ringing devices can be connected to 
each circuit. Table 4-9 lists the ringing generator output parameters. 
Table 4-9 Ringing Generator Parameters 
Parameter 
Frequency 120Hz 
Frequency Drift (for any input, output or 
temperature variation) Less than...

Engineering Information 
180 4-6 Revision 0 9104-091-l 80-NA Issue 5  

5 
’ TRANiMlSSlON 
Transmission Characteristics 
5.1 The insertion loss at 1004 Hz is as follows: 
l Station-t-Station connection: 6 dB kO.5 dB 
l Station-to-Trunk connection: 0.0 dB kO.5 dB. 
_ t 
Table 5-l Attenuation Variation 
Frequency or 
Attenuation Variation 
Transmission Plan Frequency Band (Hz) 
w/r to 1004 Hz (dB) 
Line to Line 200 0. 0 to +2.5 
300 to 3000 -0. 25 to +0.5 
3200 -0. 3 to +0.7 
Line to Trunk 200 0. 0 to +2.5 
300 to 3000 -0. 25 to +0.5 
3200 -0. 3 to +0.7 
Note: (+) is more...

Engineering Information 
Return Loss 
5.4 The Return Loss parameters in the talking state, Station-to-Station or 
Station-to-Trunk, are: 
ERL (Echo Return Loss) >I8 
dB SRL (Singing Return Loss) >12 dl3 
Longitudinal Balance 
5.5 All connections meet the following requirements with respect to longitudinal,balance: 
Minimum 
200 Hz 
58 dB 1000 Hz 
58 dB Maximum 
3000 Hz 
54 dB 
Crosstalk Attenuation 
5.6 The minimum crosstalk attenuation between any two established connections 
through the DPABX when both...

Transmission 
System Impedance 
5.8 System impedances are: 
l 600 ohms nominal for Stations 
l 600 ohms nominal for Trunks with selectable Balance Impedance of 600 ohms or 
Complex Impedance (350 Q plus 1000 Q in parallel with 0.21 pF). 
Envelope Delay 
5.9 The maximum envelope delay, Station-to-Station or Station&-Trunk, is: 
515 ys between 400 Hz and 600 Hz, 
320 us between 600 Hz and 1000 Hz, 
150 t~s between 1000 Hz and 2600 Hz, 
320 ps between 2600 Hz and 3000 Hz, 
515 ps between 3000 Hz and 3200...

Engineering Information 
180 5-4 Revision 0 
9104-091-l 80-NA issue 5  

6 
’ LINE CARD OPERATION 
ONS/OPS Line Card Operation 
6.1 When a telephone goes off-hook, the line circuit detects the flow of loop current and 
signals the Main Processor on the Control Card. The processor responds by 
connecting a DTMF receiver to the line and sending dial tone to the set. (If the set 
uses pulse dialing, then the processor detects the pulses. by monitoring the loop 
current). The user can then dial the desired number. 
When a call is directed to a station, the system applies ringing...