Mitel SX-200 DIGITAL Pabx Engineering Information Manual

							Troubleshooting 
APPENDIX C 
TWOUBLE§H0081NG KllT 
Cl.01 
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The following is a recommended list of items required in the 
Field Service Engineering Troubleshooting Kit: 
One of each circuit card as a spare, including modules 
Butt set 
Digital multimeter 
Moving coil multimeter 
Static strap 
Ground mat 
Assorted screwdrivers, wrenches 
Long nose pliers 
Spare fuses 
Wire strippers 
Fan filter. 
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							Troubleshooting 
APPENDIX D 
LOOP CURRENT MEASUREMENT 
D1.O1 There are two methods available to measure loop current: 
0 In-Line method. 
0 Voltage conversion measurement. 
If it is not possible to break the loop (i.e., open the Tip or Ring lead) 
the second method may be used: however, it is not as accurate. 
D1.02 In-Line Method. The procedure for the in-line method of 
measuring loop current is shown in Figure Dl-1 and is de- 
scribed as follows: 
I. Open either the Tip or Ring lead of the trunk facility by remov- 
ing one of the bridge clips on the MDF. 
2. Insert an ammeter where the clip was. 
3. Take current readings at the instant the trunk is seized, and 
after the call has been completed. Do this in both incoming and 
outgoing directions 
4. Release the trunk and repeat the measurements several times 
on the same Central Office at peak and low traffic hours. 
5. Repeat the above using different Central Office trunks. 
81.03 Voltage Conversion Method. This method of loop current 
measurement should be used only in such instances when it is 
not desirable to open the Tip or Ring leads. The procedure is as 
follows: 
1. 
With the trunk seized, use a voltmeter to measure the voltage 
between the Tip and Ring of the trunk. 
2. This voltage is then used to calculate the loop current (see 
below). 
3. Release the trunk and repeat the measurement several times 
using the same Central Office trunk at peak and low traffic 
hours 
4. Repeat the above measurements using different Central Office 
trunks. 
5. Typical equivalent resistance seen between Tip and Ring, when 
the trunk is seized, is approximately 250 ohms. 
Page D-l  
						

							Troubleshooting 
MDF 
BRIDGE CLIP 
TRUNK FACILITY 
5512ROEI 
Figure Dl-1 In-Line Current Measurement 
Page D-2  
						

							Troubleshooting 
6. The following is a simple calculation used to obtain the loop 
current value: 
Loop Current = measured Tip to Ring voltage 
250 
Page D-3/3  
						

							Troubleshooting 
APPENDIX E 
LOOP START VS GROUND START CHECK 
El.01 
1. 
2. 
3. 
4. 
5. 
6. 
7. The loop start vs ground start check should be performed as 
follows (also refer to Figure El-l): 
Locate the PBX trunk circuit Tip and Ring on the connecting 
block at the MDF. 
Remove the bridge clips on the Tip and Ring (i.e., disconnect 
the PBX trunk circuit from the Central Office Tip and Ring). 
Connect the butt set across the Central Office Tip and Ring. 
Go off-hook with the butt set. If Central Office dial tone is 
returned, then the Central Office trunk is loop start. 
If no dial tone is returned, then momentarily ground the Ring 
lead with a butt set off-hook across Tip and Ring. If Central 
Office dial tone is returned, then the Central Office is ground 
start. 
If still no dial tone is returned, repeat the previous step and 
ground the Tip lead instead. If Central Office dial tone is re- 
turned, the Central Office trunk is ground start (however, the 
Tip and Ring are reversed). 
If still no dial tone is returned in either of these cases, there is 
a problem (perhaps Tip and Ring opened or shorted, or a large 
ground differential between PABX ground and Central Office 
ground.) Check PABX ground. If PABX ground is good, then 
report problem to telephone company. 
Note: 
In most cases with ground start trunks, dial tone may be 
returned by grounding either Tip or Ring. If this should occur, 
repeat the 5th and 6th steps using the butt set in its 
“on-hook” or “monitor” state. Hold the ground lead on for a 
few seconds; CO should return dial tone as long as the 
ground lead is connected. 
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							Troubleshooting 
CONNECTING BLOCK 
TO PABX 
TRUNK CIRCUIT 00 TO CENTRAL 
OFFICE 
00 
HOOK SWITCH 
Figure El-l Loop Start Versus Ground Start Check 
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							Troubleshooting 
APPENDIIX F 
IWTEL REPAIR TAG 
General 
F1.01 Any card or any other device found faulty must be returned 
with a Mite1 Repair Tag (see Figure Fl-1). The following in- 
formation must be included on the repair tag: 
1. 
2. 
3. 
4. 
5. 
6. 
7. 
8. 
9. 
10. 
11. 
12. 
13. The date on which the device was returned. 
The location of the point of origin (the installation site). 
The company name. 
The product name (i.e., SX-200@ DIGITAL). 
The system serial number (located on the front of the cabinet). 
The software generic (i.e., GENE,RlC 1001). 
The software Revision (i.e., 480PB46.6 9-SEP-1986). 
The assembly part number of the item being returned (i.e., 
DTMF Receiver Module - 9019-016-OOO-NA). 
The assembly serial number of the item being returned - this is 
a white sticker located on the card itself. 
Any pertinent alarm/error displays; this may include circuit card 
alarm LEDs, 7-segment displays, console or maintenance termi- 
nal error messages, or maintenance log messages. 
A brief description of the symptoms of the problem. 
Indicate whether the fault occurred during installation, or while 
the system was in service. 
Include any further information that may be useful on the rear 
of the repair tag. 
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							Troubleshooting 
For Customer Use 
1. Date: 
2. Location: 
3. company: 
4. Product Name: 
5. System Serial No.: 
6. Software ID Generic: 
Revision: 
7. Assembly No.: 
8. Assembly Serial No.: 
9. Alarm/Error Displays: 
11. Failure Occurred A) During Installation 
8) In Service Further Details 
issue 3 
CAUTION: PLEASE ENSURE PCB ASSEMBLY IS 
RETURNED IN ANTISTATIC BAG. 
M0013RO 
Figure Fl-1 The Mite1 Repair Tag 
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							Troubleshooting 
ABPENQIX 6 
CALL PROCESSING INFORMATION 
G1.O1 
1. 
2. 
3. 
4. 
5. 
8. 
7. 
8. 
9. 
10. 
11. 
12. 
13. 
94. 
15. 
18. 
17. - Digital Bay to Digital Bay Call 
The Main Control Card (MCC) scans for on-hook/off-hook 
change of state. 
An extension goes off-hook in Bay 1. 
The MCC detects the off-hook during its line card scan. 
MCC checks for the COS of the extension to determine if the 
call is allowed. 
The MCC checks for an idle receiver. 
The MCC connects the DTMF receiver to the line circuit through 
the DX matrix on a PCM channel. 
The MCC connects the same channel to the Digital Signal Pro- 
cessor (DSP) to provide dial tone. 
The MCC monitors the circuit for rotary pulses. 
The DTMF receiver detects any DTMF tones and sends a mes- 
sage to the MCC indicating the value of the dialed digits. 
On receipt of the first digit, the MCC removes the DSP from’ the 
assigned channel. 
The MCC monitors the digits dialed and checks the idle/busy 
condition of the destination. 
If the destination is idle, the MCC connects the DSP to the 
originator and ringback is supplied. 
The MCC sends the originator a cadence message to provide 
interruption of the ringback tone. 
The MCC sends ringing to the Bay Power Supply from the DSP 
via a DX link. 
The Bay Power Supply amplifies and routes the ringing to the 
destination 
The MCC sends a message to the destination to turn ringing on. 
When the destination answers, the MCC detects the off-hook 
change of state. 
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							Troubleshooting 
18. 
19. 
20. 
21. 
22. 
G1 .I92 
1. 
2. 
3. 
4. 
5. 
6. 
7. 
8. 
9. 
IO. 
11. 
12. 
93. 
14. 
15. Ringing is removed from the destination. 
Ringback is removed from the originator. 
A channel is connected between the originator and the destina- 
tion. 
The MCC scans for on-hook/off-hook changes of state. 
When an on-hook is detected, the MCC removes the channel, 
and the call is terminated. 
- Analog Bay (Rotary) to Analog Bay Call 
The Scanner card scans the line circuits for on-hook/off-hook 
changes of state. 
An extension goes off-hook in Bay 3. 
The Scanner detects an off-hook during the line card scan. 
The Scanner sends an IRQ to the Peripheral Control Card (PCC). 
The PCC determines the originator, generates a message and 
passes it to the Digital Interface Card (DE). 
The DIC formats and sends a message to the MCC. 
The MCC checks the originator’s COS to determine if the call is 
allowed. 
The MCC checks for an idle DTMF receiver. 
The MC6 sends a message to the PCC to connect a junctor to 
the originator. 
The MCC assigns a channel of the link to the junctor, and 
conects the DTMF receiver to the channel through the DX ma- 
trix. 
The MCC connects the same channel to the DSP to provide dial 
tone. 
The PCC monitors the circuit for rotary pulses. 
The DTMF receiver detects any DTMF tones and sends a mes- 
sage to the MCC indicating the value of the tones 
On receipt of the first digit, the MCC removes the DSP from the 
assigned channel. 
The MCC monitors the digits dialed and checks the idle/busy 
condition of the destination 
Page G-2