Mitel MIVOICE OFFICE 250, Руководство по установке и администрированию

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MiVoice Office 250 Installation and Administration Guide
244
Station Loop Resistance Test
Do not use shielded cable. Achieve longer loop lengths by using heavier gauge cable, such as
22AWG. (For additional station cabling requirements and loop limits, see page 152.)
Perform the loop resistance test for each station cable individually.
1.
With a U.S. system only
, ensure that bridging clips have not been installed on the station blocks
and that the station instrument is not connected to the modular jack assembly.
2.
With a U.S. system
, place a short across the BLACK/YELLOW wires (digital telephones) or
RED/GREEN wires (single line phones) on the modular jack assembly.
With a European system
, place a short across the WHITE/BLUE wires (digital telephones) or
BLUE/WHITE wires (single line phones) on the line jack unit assembly.
3.
With a U.S. system
, at the MDF, measure the resistance across the TIP and RING wires on the
right (station) side of the station block.
With a European system
, at the MDF, measure the resistance across the WHITE/BLUE wires
on the lower (station) side of the station block.
The reading should not exceed the limits listed in
Table 43 . The resistance values (in ohms)
indicate loop measurements; the distance values (in feet/meters) indicate the maximum one-way
measurements from the equipment chassis. If necessary, longer loop lengths can be achieved
by using a heavier gauge cable, such as 22 AWG (22 gauge thickness or larger—smaller number
gauge = larger, or thicker, diameter).
4. Remove the short after the test is complete.
5. Repeat this test for each station cable.
6. With a U.S. system only, install bridging clips on the station blocks to complete the cable
connections.
IMPORTANT
Excessive and/or improperly made connections increase the resistance of a cable,
which reduces the allowable cable run length.
Table 43: Loop Limits for Digital and Single Line Phones and Equipment
Phones Port
Impedance
Loop Limit
(24 AWG)
From Base Server chassis:
• To a single line phone or playback device connected to the built-in port
• To a single line phone or playback device driven by a SLM-4 port
From DEI chassis: To a single line phone or playback device driven by
a SLM-8
600

2000 ft
(609 m)
REN 3.0
From DDM-16 (HX only) or DEI chassis:
• To digital telephones
• To a digital telephone equipped with PCDPM and MDPM and
connected to PKM/DSSs or SLA
62

1200 ft
(366 m)
From an MDPM: To a single line phone 195

3800 ft
(1158 m)
From an SLA: To single line phones or playback devices. Supports
facility code OL13C.
800

15,560 ft
(4742 m)