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#95686 12/06/09 09:15 AM
Joined: Dec 2005
Posts: 7,056
RIP Moderator-Mitel, Panasonic
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RIP Moderator-Mitel, Panasonic
Joined: Dec 2005
Posts: 7,056
I figure I can probably get the answer here easier than wading around the Avaya web site. frown Does the Definity TN746 station card support message waitng? Thanks, John C.

When I was young, I was Liberal. As I aged and wised up, I became Conservative. Now that I'm old, I have settled on Curmudgeon.
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#95687 12/06/09 06:48 PM
Joined: Sep 2004
Posts: 719
Joined: Sep 2004
Posts: 719
Yes it does


#95688 12/07/09 12:22 AM
Joined: Nov 2009
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Joined: Nov 2009
Posts: 21
TN746 Analog card supports message waiting indication..


#95689 12/07/09 10:18 AM
Joined: Dec 2005
Posts: 7,056
RIP Moderator-Mitel, Panasonic
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RIP Moderator-Mitel, Panasonic
Joined: Dec 2005
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Thanks, guys. Although the Internet has a wealth of info, most web-sites are kinda klunky and confusing, unless you visit them often, or bookmark the exact page you want to use. Or, maybe, it's a combo of me and this new-fangled typewriter. smile

When I was young, I was Liberal. As I aged and wised up, I became Conservative. Now that I'm old, I have settled on Curmudgeon.
#95690 12/27/09 10:22 AM
Joined: Dec 2008
Posts: 41
Joined: Dec 2008
Posts: 41
tn742 or tn742B analog 8 port (supports fax, answering machines, modems,
off-premise extensions, led message waiting) ringer equivalence. REN .3

tn746 or tn746B analog 16 port (short loop range up to 1900 ft. - supports fax,
answering machines, modem, neon / led message waiting, external alert ringers,
strobe queue lamps, paging circuits) ringer equivalence REN .5

*The TN-746 can only be used for ONS applications with
loop lengths under 3100 feet. However, the TN-746B can
be used for either ONS or OPS applications, and has a
distance limit of 20,000 feet.

*The TN-746 will not support model 7101 or 7103 analog
voice terminals - the TN-746B will.

*The TN-746 will not support auxiliary equipment such
as line status indicators, fax machines, answering
machines, modems or amplifier handsets - the TN-746B

*The TN-746 can have up to 4 ports ringing simultaneously
the TN-746B can have up to 6 ports ringing simultaneously.

tn769 analog 8 port (supports fax, answering machines, modems, off-premise
extensions, neon / led message waiting) ringer equivalence REN .3

tn793 or tn793B analog 24 port (supports fax, answering machines, modems,
off-premise extensions, neon / led message waiting, callerID phones, external
alert ringers, strobe queue lamps, up to 24k ft. on 22 gauge wire)
ringer equivalence REN .5

These notes summarize the key Analog Line operating requirements of TN742, TN769
and TN746 line cards.

TN746, the 16-port Analog Line circuit, is a low cost, analog tip-ring
interface. To achieve a low cost, loop range, protection, transmission and
bridging restrictions have been levied as compared with the TN742 Analog Line
card. The 8-port TN742 Analog Line, now also cost reduced, should continue to
provide full functionality wherever TN746 falls short.

Briefly, TN746 loops are limited to 1900 feet of cable, and the environment must
not be exposed to lightning. It should also be noted that the TN746 loop range
is contingent on a -48VDC power supply regulation of 2%. If a DC or "Flex"
power supply is used, loop range with some sets may be limited to 800 feet.

1. Background

There are three port circuit packs in the System 75 family that support analog
line interfaces. TN742, starting with Vintage 11, is a full function lower cost
replacement to the TN742(V1-V10), 8-port Analog Line. TN769 is identical to
TN742 V11, except that it will also support NEON lamp message waiting sets.
TN746, the 16-port Analog Line card, has been developed as a high density, lower
cost and function, alternative to the TN742 and TN769, 8-port card. With its
16-port capability, TN746 allows System 75 to serve large line size customers
while staying in a single cabinet.

These notes provide guidelines to the proper application and administration of
the Analog Line circuits.

2. On and Off Premises

TN746 is designed to be used only on loops that are unexposed to lightning or
power induced transients. Therefore, neither primary or secondary lightning
protection is provided on the circuit card.

TN742 and TN769 are provided with complete secondary protection from line
transients. For "exposed" loops primary protection must be provided with carbon
block or gas tube devices that guarantee a maximum clamping voltage of 1500 V.

3. Loop Range - AC Powered System

TN746 is designed for use with short loops. The actual allowed length depends
on the characteristics of the cable, terminating set, and battery plant.
Assuming that standard twisted pair is used, and that the battery plant
regulates within 2% of -48 VDC, the loop ranges for 22, 24 and 26 gauge loop for
all terminal types, is 1900 feet.

TN742 and TN769 have a much greater loop range as shown in Table 1.

4. Loop Range - DC Powered System

Some customers, especially those with unreliable AC mains, may desire to power
the system from a battery plant. In many DC powered configurations, little
regulation is provided on the -48VDC bus. Similarly, the multiple output "Flex"
power supply, currently under consideration for System 75 R?, has a realistic
lower limit of -44VDC. Consequently this bus is allowed to vary from -42 to
-53V. Where the -48V supply is allowed to vary this much, the use of TN746 is
severely limited. In the DC or Flex powered configuration, the maximum loop
length for 7100 series sets is 800 feet. If a loop range of 1900 feet is
required, only the 2500 type set may be used. For a summary of loop ranges see
Table 2.

On premises application of TN742 and TN769, are unaffected by battery plant
variations. However, while off-premises switch-hook supervision and rotary
dialing is provided out to 1300_Ohms, station set touch-tone pad operation will
be limited. Loop ranges, for fully operational tone sets, are as shown on
Table 1.

5. Supported Station Sets

The following station set types - the 500, 2500, 7101, and 7103, with LED
message waiting only, are supported by TN742. In addition to supporting all the
above mentioned station types, TN746 and TN769 support 2500 type NEON lamp
message waiting sets.

6. Ringer Equivalance

TN746 has a ringer equivalence number (REN) of 5, while the cost-reduced TN742
and TN769, like their TN742 predecessor, has a REN of 3. This is based on a
75-100VRMS ringer source and the maximum loop range for each respective board.

With the electronic tone ringer load of ~0.5 REN, a REN of 5 and 3 will allow up
to ten and six electronic ringer loads to be paralleled, respectively. Today,
even 2500 type sets are now manufactured with electronic tone ringer circuits.

7. Message Waiting

For the sets mentioned above, both TN742 and TN746 are compatible with low
voltage LED message waiting lamps. In addition, TN746 and TN769 provide a high
voltage signal for the KS19527L1 and L2 NEON message waiting lamps. For neon
message waiting a TN752 Power Unit is required. The TN752 replaces the TN736 -5
VDC supply, with a -5 VDC and -150 VDC power supply.

8. Station Set Bridging

Based upon telephone set performance criteria TN746 has the following bridging

1. No more than two station sets bridged (on-hook) per line. Only one of the
bridged sets may have LED message waiting.

2. The 7103 set may not be bridged.

3. The total loop length, from switch to station set, may not exceed those

4. Only one station set is off-hook at a time. If more than one set is off-
hook transmission performance will be significantly degraded.

Where off-hook bridging is required, TN742 and TN769 may be used provided that-

1. The 7103 set may not be bridged.

2. No more than two sets are bridged.

3. Only one set has LED message waiting.

4. Neither bridged loop exceeds loop limits of Table 1.

9. Transmission Performance

Due to reduced set voltage and current, transmission performance of the TN746
has been optimized for the 2500 type station set. Some customers may be
sensitive to slightly higher sidetone, or find it difficult to hear weak speech
in a noisy environment with the 7100 series sets. In these cases 2500 series
sets are recommended.

10. Summary

The limitations of the TN746 line card can be summarized as follows;

1. Total loop length should not exceed 1900 feet. With some power
configurations the loop range is limited to 800 feet.

2. All TN746 loops must NOT be exposed to lightning or power induced

3. Off-Hook bridging is not supported.

On-Hook bridging is allowed, except with 7103 sets, as long as only one
set is of the LED message lamp type.

4. Where sidetone or "can't hear", (e.g high ambient noise environments)
complaints are experienced, 2500 sets should be used.
                                  TABLE 1

|          TN742 & TN769 ANALOG LINE LOOP RANGES - TIGHTLY REG. -48VDC(2%)     |
| Set Model |  Cable Gauge|  Loop Range|  Loop Resistance|         Comments    |
|_____________________________________________________________________________ |
|7100 Series|      26     |    10Kft   |      822_Ohm    |             #*      |
|----------------------------------------------------------------------------- |
|7100 Series|      24     |   15.2Kft  |      822_Ohm    |             #*      |
|----------------------------------------------------------------------------- |
|7100 Series|      22     |    25Kft   |      822_Ohm    |             #*      |
|----------------------------------------------------------------------------- |
| 500/2500  |      26     |    13Kft   |     1100_Ohm    |280_Ohm(DC),20mA set*|
|----------------------------------------------------------------------------- |
| 500/2500  |      24     |    20Kft   |     1100_Ohm    |            " *      |
| 500/2500  |      22     |    30Kft   |     1100_Ohm    |            " *      |

|       TN742 & TN769 ANALOG LINE RANGES - LOOSELY REG. -48VDC(-42 to -53) +   |
| Set Model |  Cable Gauge   Loop Range   Loop Resistance           Comments   |
|7100 Series|      26     |     7Kft   |      570_Ohm                  #*      |
|     "     |      24     |   10.5Kft  |      570_Ohm    |             #*      |
|     "     |      22     |    17Kft   |      570_Ohm    |             #*      |
| 500/2500  |      26     |    9.5Kft  |      800_Ohm    |280_Ohm(DC),20mA set*|
|     "     |      24     |    15Kft   |      800_Ohm    |             " *     |
|     "     |      22     |    24Kft   |      800_Ohm    |             " *     |

  + All sets are fully operational.

  * Select OPS administration option if loop length exceeds 3.5Kft.

  # 7100 series sets are not registered.  They should therefore not appear on
    OPS loops that go through the CO.

                                  TABLE 2
     |      TN746 ANALOG LINE LOOP RANGES -TIGHTLY REG. -48VDC(2%)      |
     | Set Model|  Cable Gauge|  Loop Range|  Loop Resistance|  Comments|
     | All sets |     26-22   |  1900 feet |         -       |          |

|          TN746 ANALOG LINE RANGES - LOOSELY REG. -48VDC(-42 to -53) +       |
| Set Model |  Cable Gauge|  Loop Range|  Loop Resistance|        Comments    |
|7100 Series|     26-22   |   800 feet |         -       |                    |
| 500/2500  |     26-22   |  1900 feet |         -       |280_Ohm(DC),20mA set|

A great teacher, does not provide answers, but methods to teach others "How and where to find the answers"


36 years Bell, AT&T, Lucent, Avaya
Tier 3 for 26 years and counting
#95691 12/27/09 12:42 PM
Joined: Nov 2001
Posts: 1,640
Joined: Nov 2001
Posts: 1,640
Good Info Tier 3

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