Inter-Tel Imx/Gmx 256 Installation And Field Maintenance Manual

							lNTEIbTELPR4mcESJMX/GMX 256 INSTALLATION & MAINTENANCESPECIFICATIONS
Issue 1, November 1994B. 
TRUNK CONNECTIONS
2.6The CO, DID, and E&M trunks are terminated on
telephone company RI-type blocks, as required by FCC
regulations. Cross-connect cable is used to connect theRI-type blocks to the CO, DID, and E&M terminal
blocks on the MDF. The trunks are then connected to theLoop/Ground Start Cards 
(LGCs), Loop Start Cards
(LSCs), Inward Dialing Cards (IDCs), and/or E&M
Cards (E&Q) using industry-standard, 25-pair cable.
Female 
50-pin amphenol-type w~ectors on the cables
attach to the male connectors on the cards.
2.7To meet Part 15 of FCC Regulations, all trunk
cables must be equipped with ferrite beads. *o ferrite“split” beads (two half beads) are installed on each
25-pair cable just below the amphenol-type connector.
The beads help to reduce electromagnetic interference
(EMI) and radio frequency interference (RFI).
NOTE: Each ferrite split bead, which is actually half ofa full bead, is ordered individually (see REPLACE-
MENT PARIS for the part number). Two split beads are
required to form one complete bead.
2.8
Tl spans are terminated on telephone company
RJ4gC modular jacks (or on RI-type blocks that are thencross-connected to modular jack assemblies), as re-
quired by FCC regulations. Four-pair, non-reversing,mod-to-mod line cord is used to 
connect each Tl span
directly to the 
Tl jack on the corresponding Tl Card.(Or, to use the optional DB15 connector instead, 
see
page 3-20.)23
It is recommended that gas discharge tubes with
silicon avalanche suppressors be installed on all 
non-T1
trunks for lightning protection. (For 
Tl spans, the CSU
itself provides the lightning protection.) Also, in areaswith frequent occurrences of lightning, it is recom-
mended that the cable between the telephone company
termination and the gas discharge tubes be at least 75
feet long (the cable may be coiled up if desired).
2.10The 256 System has the following trunk charac-
teristics:
LosshxxCO to keysetCO to .single4ne setcotocoRinger quivalenca
Ringing voltage
Ring frequency
Loop 
currcnt
&m (@lLHz, 0 fL)CUB (@lLHz 0 fQodB @W-k 0 k)0.6B4ovRMsminimum17-63I-h2chnAminimum
l-$-to-ring4OOV transient
Page 2-5 
						

							SPECIFICATIONSIssue 1, November 1994lNTER-TELPBAcIIcESIMX/GMX 256 INSTALLATION & MAINTENANCE
3. EQUIPMENT CABINET
A.EQUIPMENT CABINET DESCRIPTION
3.1 The 256 equipment cabinet houses the system
power supply, the Telecom Motherboard, a 17-slot card-
ftle assembly, and the circuit cards, including: ROM
Central Processing 
Unit (RCPU) Card, Tl Cards
(TlCs), E&M Cards (EMCs), Loop/Ground Start CardsI
(WCs), Loop Start Cards (LSCs), Digital Keyset Cards
@KS&), Keyset Cards (KSCs or KSC-Ds), Single-
Line Cards 
(SLCs), and Inward Dialing Cards (IDCs).
3.2
Hquipment cabinet dimensions are as follows:Height
26.0 in. (66.0 cm.)
Width32.0 in. (81.3 an.)
Depth23.0 in. (58.4 cm.)
Weight
- Empty98 lbs. (44 kg.)- Loaded146 lbs. (66 kg.)B. 
FCJNCTIONAZ DESCRIPTION
3.3Together, the circuit cards in the equipment cabi-
net perform the switching activities for the system; de-
tect incoming calls, process data-controlled features;
control the interaction of station instruments, trunks,
and intercom calls; etc.
3.4The system is a microprocessor-controlled, pulsecode modulation 
(PCM), time-division multiplex
(TDM) system. Memory includes 512k bytes read-only
memory (ROM) and 
512k bytes random access memory
(RAM) on the ROM Central Processing Unit 
(RCPU)
Card. 
In addition, each keyset contains a microproces-
sor that communicates via a 
Keyset Card with the mi-
croprocessor on the RCPU Card.
3.5The 256 circuitry and software combine to pro-
duce an “integrated switching matrix” of 256 time slots
(8 PCM highways 
Ibuses] x 32 time slots). Of the 256
time slots, 32 are reserved for conferencing and four are
reserved for 
MMP decoders. If additional M’MF de-
coders are installed (up to four), additional time slots are
also reserved. This leaves between 216 and 220 time
slots available for voice channels. (For a diagram of the
system voice channel allocation, refer to Figure 2-l onpage 2-7.) Therefore, the total number of 
non-block-
ingvoice channels available ranges from 216to 22O(de-
pending on the number of additional 
IYTMP decoders
installed on the RCPU Card).
3.6Whenever there is a change in the system’s circuitcard 
con&uration, all equipped cards are assigned to
one of the PCM highways (also called buses). The indi-
vidual circuits on each card may use only those voice
channels available on the assigned PCM highway. Thesoftware automatically distributes the cards to 
make the
best possible use of the available voice channels.
-\,:j.:
3.7If there is a large mrmber of cards installed, two or
more cards may be assigned to the same PCM highway.
The voice channels on each PCM highway are then allo-
cated to the assigned cards for outside calls, intercom
calls, and pages on a first-come, first-served basis. Since
each two-way conversation requires two voice chan-
nels, the maximum number of simultaneous two-way
conversations available ranges from 
108 to 110.
3.8If, on a single 
PCM highway, there are more ports
equipped than there are voice channels, there is a remote
possibility that all the voice channels could be in use at
one time (see Figure 2-l on page 
2-7). If this happens,
a user attempting to place a call or page hears reorder
tones and must try again (the system also generates an
error message to indicate that no voice channels were
available). Generally, a voice channel will be available
on the second attempt.
NOTE: It is possible to equip more ports than there areavailable voice channels, especially when installing a
number of Tl spans, single-line sets, digital keysets, or1
8-line IMX AIM keysets installed two to a circuit. (In
fact, the programmer can equip up to 256 ports.) For to-
tal non-blocking applications, it is necessary to limit the
number of circuit cards installed in the cabinet. (Refer to
PROGRAMMING, page 5-172, for information on des-
ignating certain circuit cards as non-blocking and gen-erating voice channel allocation data for 
traffic
analysis.)
3.9As many as nine external paging ports can be usedfor 
comtecting external paging speaker equipment.
Each external paging port requires au available SLC,
LGC, or LSC circuit.
NOTE: When installing external paging equipment on
an LGC or LSC circuit, use a paging amplifier that pro-vides talk battery. When installing external paging
equipment on an SLC circuit, use a paging amplifier that
DOES NOT provide talk battery.Usmg a pagmg amplifier 
wrth talk battery on an
3.10The 256 System has two music channels. If de-
sired, two different music-on-hold sources (port 1 
and
port 2) maybe connected to the RCPU Card. By entering
a feature code, individual 
keyset users can choose to lis-
ten to background music from either of the two musicsources. Internal users will also hear music 
from the
selected source when on hold and when camped on. For
outside callers, the source for the Music-On-Hold 
fea-
ture is assigned on a trunk group-by-trunk group basis.
-~‘\,:j;;..-
Page 2-6 
						

							INTER-TELPRACTIcEsIW4GMX 256 Il’iSTALLA’I’ION & MAINTENANCESPECIF’I~~ONSIssue 1, November 1994
3.11The card slot on the far right (17th slot) of the
cabinet is reserved for the RCPU Card. 
Other than that,card slot must be entered through database 
program-ruing. See page 5-170 in 
PROGRAMMING.-any station or trunk card may be placed in any of the re-
maining 16 slots.
NOTE: Information on the type of card installed in each3.12The Telecom Motherboard power cable, which
comes alreadv installed in the equipment cabinet, con-
nects the 
systim power supply to the Telecom Mother-
board.
FIGURE 2-l.VOICE CHANNEL ALLOCATION
123
45
32 voke52 voiceChannels ChannelsS2Vdtcb
Channels32VOkO
Channels52 voiceChannels
EOUIPMENT CABINET -5 PCM HIGHWAYS WITH 22 TIME SLOTS PER HIGHWAY
‘.-.-.--1
VOICE CHANNELS
AVAILABLE
pq/n-
SAMPLE ALLOCATlON FOR ONE PCM HlGHWAY
NOTE: The above example shows a sample voice channel allocation for one PCM highway (voice
bus) in a heavily-loaded equipment cabinet. The system has assigned one 
Tl Card, one Single-Line
Card, and one 
Inward Dialing Card to the same PCh4 highway. If all three cards are designated as
“blocking” in database progr
amming, the 48 circuits will vie for the 32 voice channels on a first-
come, first-served basis. If, however, the 
Tl Card is designated as “non-blocking,” the system will
rebalance the cards so that the 
Tl Card is assigned to a highway that has no more than 32 equipped
ports. (Refer to 
PRGGRAMMING,page 5-172, for information on designating certain circuit cards
as non-blocking and generating voice. channel allocation data for 
tra5c analysis.)
Page 2-7 
						

							SPECIFICATIONSINTER-TELPRACTICES
Issue 1, November 1994IMX/GMX 256 IN-TION & MAINTENANCE
c. 
ENvrRoIvMENmLREQUIREMENTS
3.13 The equipment cabinet and the station instru-
ments require the following environmental conditions:
#OPERATlON
Temperature32’ to 104” F-40°t0185’F(Cabinet)O”t0 4o”c-4WtOSS”C
Temperature32” to 
113’ F-40” to 185” F(Station Instruments)o”to 4Yc40°t08S”C
Relative Humidity5% to 95%5% to 95%
(Non-condensing)
AltiNdeup to 10,000 ft.Upto40,OOOR
(3,048 m.1(12,192 m.)
NOTE: It is recommended that the maximum operatingtemperature (as stated above) 
never be exceeded.
Therefore, when iustalling the equipment cabinet and
station iustruments, allow a sufficient margin for error
in case of air conditioning failure, routine mechanical
maintenance, plant shutdown, etc. As a general guide-
line, if the conditions are suitable for office 
personnel,
they are also suitable for all equipment and station in-
strument operation. A properly controlled environment
will help to extend the operating life of the equipment.3.14 While in operation, a fully-loaded equipment
cabinet generates approximately 1,000 British Thermal
Units 
(BTUs) of heat per hour. The maximum amount of
heat generated per individual station instrument is 6.8
BTUs per hour.
NOTE: This information is provided so that any cooling
needed to meet the proper environmental conditions (as
listed in the chart) can be calculated.
D.SYSTEM POWER SUPPLY
3.15The 
system power supply is installed to provide
power to the circuit cards and to all stations. The power
supply itself is comprised of a metal chassis with variousmodules installed.
3.16The power supply must have an isolated, dedi-
cated, 
10%12!5VAC, HA, 57-63H2, single-phase corn-mercial power source (for details, refer to the first
NOTE on page 3-3 in INS’WLLAIION).
3.17All systems are equipped with one Quad Module
(+5V, -5V, +12V, and -12V) and one Master 30V Mod-
ule. Depending on the number and type of 
keysets in-stalled, one or two Slave 30V Modules may also be
needed (see the following paragraph for details). If anyAC-ringing single-line devices are to be used, a 
Ring
Generator Module must be installed. If any SLCs, IBCs,
LGCs, or EMCs are used, a -48V Module must be in-stalled. 
KSCs, LSCs, and TlCs do not use -48vDc.(Refer to REPLACEMENT
PARIS for the part num-
bers of the various power supply modules.)
3.18Based on the number of dual-circuit 
8-line IMXAIM 
keysets and other-type keysets installed, the fol-
lowing chart can be used to determine the number of
Slave 30V Modules needed. (The programming PC will
also display a message if an additional module is need-
ed.) If it is determined that two Slave 30V Modules are
needed, a version C power supply chassis and version C
power supply modules must be used (see paragraphs
3.21 and 3.22).(S-line 
AIhis X 0.0755) +(other analog keysets X 0.125)+ (digital 
keysets X 0.060) = y
If y ( 8, only the Master 30V Module is re-
quired.
Ify 
> 8, but ,( 16, one Slave 30V Module is
also required.
Ify > 16, two Slave 30V Modules are also
required.
I
3.19Located on the front side of the power supply
chassis are the ON/OPP power switch, a 1OA or 15A
fuse that isolates the AC power source from the system,
and the removable cover plate.
3.20Located on the back side of the power supply
chassis are the AC power cable, all of the connectors for
the various power cables, 
and a grounding lug to con-
nect the equipment cabinet to an earth ground.Power Supply Modules
3.21Currently, there are three versions of power sup
ply modules used on the 256 System: (A) part numbers
440.0102-0106, 
(B) part numbers 440.01% 0122, and
(C)part numbers 
440.0112- 0115. (Refer to REPLACE-
MENT 
PARTS for a complete list of the part numbers.)
3.22Version A and B 
power supply modules are com-
patible with each other, and they use the same chassis.
However, due to numerous design enhancements, ver-
sion C modules and chassis are not compatible with ver-sions A 
and B. Either use all version A and B power
supply modules and chassis, or use all version C mod-
ules and chassis. 
Do not mix the two @pes.
4.  
. . .
Page 2-8 
						

							INTER-TELPRACTICESIM.X/GMX 256 INSTACLATION & MAINTENANCESPECIFICATIONSIssue 1, November 1994
3.23The version A Ring Generator Module has a 3
amp fuse, while all other version A power supply mod-ules have 6 amp fuses. Maximum power outputs for
each version A module are shown below.
MOOUE-48V MODUU
+NDc, 18A-48VDC, 5A-WDC, 4A+12vDc, 6A12VJ.X, .5AMASTER 
SLAM
+3ovDc, 8A+3ovDc, 8A
NOR MODULE
90VAC 
0,2OWRing Frequency, mI-k
3.24Except for the Quad Module (SA fuse, +WDC
output of 23A, and +12VDC output of 4A), version B
and C power supply modules have the same fuses and
maximum power outputs. Also, there is only one version
C 
3OV Module, which can be used as either a master or a
slave.NOTE: For easier power supply module removal, each
version C power supply chassis is shipped with an ex-
tractor tool attached to the inside, front cover. The ex-
tractor tool may be used with version B and C modules
only.Voltage 
Sutge and Spike Protection
3.25To reduce the effects of AC voltage surges and
spikes that may cause system malfunctions, false logic,
and/or damage to the electronic components, a surge/
spike protector is provided. (Refer to REPLACEMENT
PARTS for the part number.) Its specifications are:
0Clamp voltage transients at 300VDC within 5 nano-
seconds when exposed to waveforms as described in
the 
ANSI/IEEE Standard C62.41-1980 (IEEE 587).l
Reduces RFI/EMI noise by at least 20dB at frequen-
cies between 
&I-Ix and 3OMHz.Battery Back-Up
3.26To provide back-up power in the event of a powerfailure or brownout condition, the power supply can
have optional battery back-up using a customer-pro-
vided 
uninterruptable power supply (UPS) unit or a
standby power supply (SPS) unit. Refer to page 2-32 for
more information.Page 2-9 
						

							SPECIJ?ICATIONSINTER-TELPRACTICES
Issue 1, November 1994IMX/GMX 256 INSTALLATION & MAINTENANCE
E. CIRCUITCARDS
3.27In addition to the power supply, the equipment
cabinet houses the Telecom Motherboard and the circuit
cards that control and coordinate the functions of the
system. Up to 17 cards may be connected to the Telecom
Motherboard, including:
1m l-16,
1-W1-W1-Wl-15’
l-15l-4
ROM central promsing unit (RCPU) card - rquircdKcysctCard(DKSC,KSC,orKSGD)-atlcastoneis
=w=lsiiglc!-Line card (SLqInward Dialing Card @DC)LoopF3round Start Card (LGC)Ltwpslartcard(Lsc)
=Q=d(EMc)Tl Card VlC)
l Refer to page Z-21 for station capacities.
328Descriptions of the cards are given in the follow-
ing paragraphs. Drawings of the cards are located in the
INSTALIA-ION section.ROM Central Processing Unit 
(RCPU) Card
3.29The RCPU Card contains the main controlling
IIlicroprocessor and associated control logic and
memory circuits. It is under the control of a program,
stored in the 
ROM, which is activated when the system
is powered up. ROMs containing the system software
are installed on the RCPU Card before it is installed in
the equipment cabinet.330
The RCPU Card contains the following system
resources:
lb0 RS-232-C (DB9) connectors (g-pin subminia-
ture “D” male connectors) for connecting 
SMDR/
SMDA output devices and/or a personal computerfor programming the system database (see page
2-31 for requirements).
Voltage test points for checking the system +WDC,
-5vDc, +12vDC, -12vDC, +3ovDC, -4WDC,
and AC ring voltage levels. To measure system volt-age levels, voltmeter probes are 
iuserted into the
ground test point and the desired voltage test point.
Refer to 
INSTXLATION, page 3-45, for details.LED 
indicators show main processor operation
(CPU ACTIVE), major system alarms (MAJOR
ALARM), minor system alarms 
(h4lNOR
ALARM), database error occurrences 
(DAlXBASEERROR), database back-up battery connection
(BAZTERY OFF), high power supply temperature(POWER ALARM), and external clock activity
(EXTERNAL CLOCK ACTIVE). Refer to TROU-
BLESHOOTING for detailed LED information.
0Reset 
switch is used to manually reset the system
during troubleshooting. This is a software reset (mi-
nor reset), not a hardware reset (major reset). Push-
ing this switch does the following:
- Preserves the battery-backed database iuforma-
tion, non-conference calls in progress, outside
calls being dialed 
from keyset stations, inter-sta-
tion messages, calls on individual hold, 
do-not-
disturb messages, and reminder messages. A call
on system hold is changed to individual hold at
the station that placed it on hold.
“:,
i
-Restores MMF decoders, modem access, and
speech channels, and resets the station clocks to
match the system clock. Updates trunk key, 
DSS/
BLF key, speeddial key, and feature key lamp
SMUS.
- Interrupts system operation, which disconnects
pages in progress, calls ringing 
in, calls using the
conference resources (as described on the next
page), and calls using DTMF decoders. 
Camped-
on calls are disconnected and queue requests are
canceled.
- Terminates system and user programming.Database back-up battery 
(3.6V, HAA lithium
battery) that can support the database for at least two
months of accumulated system down time.Battery voltage test points and check button for
checking the database back-up battery charge. If the
battery voltage is not greater than 
2.!WDC, replace
the battery.
Rattery back-up jumper strap for activating the
database back-up battery. The jumper strap should
be placed in the ON position (over the top two pins)
before the RCPU Card is installed. When the card is
taken out of service for repair or storage, the jumper
strap should be placed in the OFF position (lower
two pins) to preserve the battery charge.
NOTE: Placing the 
BmRY jumper strap in the
OFF position erases the database.Male 
50-pin amphenol-type connector for con-
necting up to two music sources, a power failure
transfer relay, and a general purpose relay:
-Up to two external music sources (such as radios,tape players, etc.) may be connected to the
RCPU Card. AGC circuits on the RCPU Card au-tomatically hold the volume of each music
source to a predetermined level that is slightly
lower than the normal voice volume, as requiredby FCC regulations. Optimal input level is
0.775VRMS (OdB). For installation instructions,i,;:
see page 3-99.,-JPage 2-10 
						

							INTER-TELlPRACTICESIMX/GMX 256 INSTALLATION & MAINTENANCESPECIFICATIONSIssue 1, November 1994
- Relay 1, which is the power failure transfer relay
(and cannot be 
changed),can be used to connect
one or more single-line sets to predetermined CO
trunks in the event of processor card failure or a
power failure. (If ground start trunks are used,the single-line set must be equipped with a
ground start button.) The output is a normally-
open 
DPDT relay that is held closed during sys-tem operation. Additional equipment needed
includes a customer-provided PFT relay card
and card mounting case. The RCPU Card relay
contact ratings are listed below. (See also page
2-32.)-
REICARD
0.6A at 125VAC0.6A at 1lOvDC2.OA at 30VDC
- Relay 2 can be used to activate an external sig-naling device when a call rings in on assigned
CO trunks. The dry contacts follow the normal
keyset CO ringing cycle (two seconds on/four se-conds off). Ring in for the relay can be pro-
grammed for day and/or night modes.
Or, relay 2 can be used for night switch to turn on
or off lights, an alarm system, or other devices.
The relay, which is activated when an attendant
in the designated tenant group places the system
iu night mode, causes the swing connection to
move from the “break” to the “make” position.
Or, relay 2 can be used for activating external
paging. The relay, which is activated when the
paging zone to which it is assigned is accessed by
a station user, causes the swing connection to
move from the “break” to the “make” position.
This contact can be used to activate the micro-phone input of an externally-mounted paging
amplifier.
0Music-on-hold (MOJX) jumper straps for enabling
one or both of the external music sources that areheard by callers when they are placed on hold or
camped on. If connecting an external music source,
place the associated jumper strap in the ON position
(over the top two pins). Then, in the database, each
trunk group can be assigned music port 1, music port2, silence, or tick-tones. Refer to PROGRAM-
MING, page 5-103.
0300~baud and 1200~baud modem interface for re-
mote programming.When the system is in the de-fault 
contiguration, the 300-baud Bell modem is
assigned extension number 270, the 12OO-baud Bell
modem is 271, the 
300-baud CCITT modem is 272,
and the 
1200-lbaud CCI’IT modem is 273. Any atten-
dant can transfer a call to the modem, or it can be
accessed directly using 
DISA.
Conferencing resources for connecting up to 32
parties in multiple conferences. There can be up to
10 simultaneous three-way conferences or four si-
multaneous eight-party conferences. Except for the
fact that there can be only eight parties involved in asingle conference, any combination using the 32
dedicated conference circuits is possible. The con-
ferencing resources also support the Call Forward,Call Transfer, Station Call Monitoring, and DISA
features when two trunks are connected. Conferenc-
ing utilizes a 
zero dB loss function so that there is no
substantial loss in voice volume no matter 
howmany
people are in the conference.
DTMF decoding circuits (four) are used when sing-le-line sets are dialing and when features such as
DISA and Automated Attendant are used. They are
also used for the Unsupervised CO Call Continua-
tion feature (as described in paragraph 4.88 on page
4-37). These four decoders convert DTMF signals
to the digital codes used by the system. They are in
use only while the dialed number is beii 
processed,
not for the duration of the call. If all four DTMF de-
coders are busy, the user may camp on.
NOTE: If necessary, up to four additional DTMF
decoding circuits can be added to the RCPU Card byinstalling 
lYIMF Expansion Chips (two chips per
circuit; four chips per kit). Refer REPLACEMENT
PARIS for the part number.Tone generating circuit generates DTMF tones
whenever needed by the system (for example, when
a station user uses one of the system auto-dial fea-
tures, such as LCR, Call Forward To The public Net-
work, Station or System Speed Dialing, etc.). The
circuit is also used to produce all of the system tones
(busy, reorder, do-not-disturb, etc.) heard by digital
keyset, single-line set, DISA, and automated atten-
dant users. (Analog 
keysets generate their own sys-I
tern tones.)A-law/mu-law jumper strap for choosing the
method of encoding sampled audio waveforms used
in pulse code modulation systems. Domestic tele-
phone companies use the mu-law method. The a-law
method is widely used outside of North America.
Page 2-11 
						

							SPECIFICATIONSIssue 1, November 1994lNTER-TELPRACTICESIMX/GMX 256 INSTALLATON & MAINTENANCE
4 Keyset Cards (DKSCs, KSCs, or KSC-Ds) and
Single-Line Cards 
(SLCs)331
Station instrnments are connected to the stationI
cards in the equipment cabinet. Digital keysets are con-
nected to Digital 
Keyset Cards. Analog keysets, analog
DSS/BLF Units, and Attendant Computer Consoles are
connected to 
Keyset Cards. Enhanced Single-Line Sets
(ESLSs), Single-Line Instruments (SLIs), industry-
standard single-line DTMF sets, and playback devices
are 
uxmected to either Single-Line Cards (AC-ringing
instruments only) or Inward Dialing Cards (AC or DC).
For more 
infoimation on Inward Dialing Cards, refer to
page 2-15.332
Digital Keyset Card (DKSC): Each DKSC pro-vides up to 16 circuits for connecting digital 
keysets.
Each circuit has a self-correcting 
thermistor to protect
the system 
from damage due to a short circuit in the sta-tion cabling. If a short circuit causes a thermistor to
open, it will automatically close when the short is re-
moved.
3.33Up to 50 digital 
keysets may be equipped with up
to four digital 
DSS/BLF Units each. The units are con-
nected in series to the PC Data Port Module 
(PCDPM)
on the back of the corresponding 
keyset. Unlike analog
units, digital 
DSWBLF Units do nor require station cab-
ling separate from the 
keyset’s cabling; instead, they are
powered by their own AC transformer.334
Each DKSC has a green LED (CARD ON-LINE)
to indicate the card’s functional readiness and 16 green
LEDs (CIRCUlT BUSY) to indicate whether any circuit
on the card is busy (see Figure 3-30 on page 3-48).
3.35Each 
DKSC comes equipped with one Digital
Signal Processor (DSP) that provides resources for up to
12 shared speakerphones. If desired, a second DSP can
he installed to provide an additional 12 shared speaker-
phone resources.
NOTE: For information on using shared speakerphonesfor digital 
keysets, see page 4-40 in FEAWRES.
3.36Keyset Card (KSC or KSC-D): Each KSC (or
KSC-D, see the following note) provides up to eight cir-cuits for connecting analog 
keysets, analog DSS/BLF
Units, and Attendant Computer Consoles to the system.
flUp to 50 KSC circuits can be used for installing analog
DSS/BLF Units. As many as four analog units can beconnected to a single card. Some 
KSCs have a 2A,
25OVAC, AGC 2 (fast-acting) fuse to protect the system
from damage due to a short circuit in the station cabling.
Newer version 
KSCs have eight self-correcting thermis-
tors (one for each circuit) instead of the fuse. If a shortcircuit causes a thermistor to open, it will automatically
close when the short is removed.
NOTE: To install any 
&line IMX AIM keyseta nuo to II
circuit, the new “dual-circuit” version Keyset Card
(KSC-D) must be used (see REPLACEMENT PARTS
for the part number). To install 
8-line AIM keysets one
to a cinxir, either the KSC or the KSC-D can be used.
-\.
/337
Each KSC has an LED (CARD ACTIVE) to indi-
cate the card’s functional readiness. In addition, 
eachin-
dividual circuit on each card has an LED to indicate the
circuit’s activity (lit green) or failure (lit red).
3.38 Single-Line Card (SLC): SLCs are used for
connecting AC-ringing ESLSs, SLIs, single-line DTMF
sets, and playback devices. They can also be used forconnecting external paging equipment. Off-premises
stations cannot be legally connected to SLCs; instead,
Inward Dialing Cards 
(IDCa) must be used (see page
2-15). Some SLCa have a fuse to protect the -48V out-
put. 
Thisfuse cannot be qdaced in thefield If the fuse
is defective, the entire card must be sent in for repair.
Newer version 
SLCs have a self-correcting thermistor
instead of the fuse. If a short circuit 
causea a thermistor
to open, it will automatically close when the short is re-
moved.NOTE: For optimal performance, it is recommended
that voice mail units and automated attendant playback
devices be installed on IDC circuits rather than 
SLC cir-
cuits. Doing this mutes any DTMF digits automatically
dialed by the system (e.g., those generated when 
tran-
sferriug or forwarding an outside caller to voice mail).339
Each SLC has an LED (CARD ACTIVE) to indi-
cate the card’s functional readiness. In addition, each in-
dividual circuit on each card has an LED to indicate the
circuit’s activity (lit green) or failure (lit red).
3.40Station configuration: Station instrument con-
figuration depends on the number and type of station
cards installed in the equipment cabinet. There can be
any combination of station cards allowing combinations
of 
keysets in eight-station increments (or 16-station in-crements if using digital 
keysets or &line dual-circuit 1
IMX AIM keysets) and single-line sets or playback
devices in increments of 16 (using SLCs) or in incre-
ments of eight (using 
IDCs).NOTE: At least one 
Keyset Card (DK!X, KSC, or 1KSC-D) 
~ULR be installed to provide an attendant
(equipped with a display keyset or an Attendant Com-
puter Console) that can receive system alarm messages,
program system data, act as the attendant for unsuper-
vised CO recalls, etc.
3.41Each station card circuit is assigned a hardware
address number according to the card’s slot in the equip
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							INTER-TELPlGKTICESIMX/GMX 256 IN-TION & MAINTENANCESPECIF’ICA~ONSIssue 1. November 1994
ment cabinet and the location of the circuit on the card.
For example, circuit 1.2 is the second circuit on the first
card installed in the equipment cabinet.
NOTE: In the default database configuration, there are
no 
keyset circuits assigned for 8-line dual-circuit JMX
AIM keysets installed two to a circuit (e.g., 1.2A and
1.2B).
3.42When the system is first powered up, the defaultI
configuration is used to assign extension numbers to the
station circuits. 
On IMX 256 Systems, card slots l-4 are
considered 
KSCs or KSC-Ds, slots 5-6 are DKSC!s, slots7-g are unassigned, slots 9-12 are 
SLCs, and slots
13-16 are LGCs. On GMX-256 Systems, card slots l-8
are considered KSCs or KSC-Ds, slots 9-12 are SLCs,
and slots 13-16 are 
LGCs. Changes to the default con-
figuration can be made through database programming.Refer to
PRGGRAMMING,page 5-170, for more in-
formation.
3.43The system assigns extension number 100 to sta-
tion circuit 1.1, extension number 101 to station circuit
1.2, and so on to match the initial configuration. Circuit
1.1 is equipped as the primary attendant’s 
keyset when
the system is in the default configuration. If desired, the
circuits can be assigned different extension numbers
and/or four-digit extension numbers through database
programming. Refer to
PRGGWWMJNG,page 5-58,
for more information.
NOTE: When 
8-line IMX AIM keysets are assigned todual circuits, the “B” circuits do not have extension
numbers until they are assigned in database program-
ming-
Page 2-13 
						

							SPECIFICATIONSIssue 1, November 1994INTER-TELPRACTICBIMX/GMX 256 INSTALLATION & MAINTENANCE
Loop/Ground Start Cards (LGCs) and Loop Start
~~a.=3
3.44Each LGC and LSC has circuitry for up to eight
trunks. LGC and LSC circuits may also be used for in-
stalling external paging equipment. 
LSCs can only have
loop start trunks connected to them. 
LGCs can have ei-
ther loop start or ground start trunks. Each individual
circuit on the LGC has two 
jumper straps for designating
whether the circuit is loop start or ground start. Individu-al trunks may be designated as either loop start or
ground start in database programming.
NOTE: For each LGC circuit, both jumper straps must
be in the proper 
(LS or GS) position. If the strap settings
are mixed, or if one or both of the straps is missing, the
circuit will not function properly. Also, when setting the
straps, note the unique ordering of the LGC circuits as
shown in Figure 3-34 on page 3-55.
3.45For optimal CO trunk transmission performance,
each LGC and LSC circuit should be “hybrid balanced”in database programming. Hybrid balancing refers to
selecting the balance network - ideal, loaded, or un-loaded
-that best matches the trunk’s impedance. Re-
fer to
PROGRAh4MlN
G,page 5-147, for details.
3.46Should voice transmit or voice receive volumeproblems occur, the receive gain 
and/or the transmit
gain for individual trunks can be adjusted in database
programming. Refer to PROGRAMMING,page 5-103,
for additional information.
3.47
Each LGC and LSC has 16 speciallydesigned
fuses soldered to the card to protect it from large voltage
surges due to lightning. If a fuse is open (blown), it may
mean that other parts of the card have also been dam-
aged. For this reason, open fuses must not be replaced in
the field. Instead, the entire card 
must be returned for
testing and possible repair. Failure to follow this policy
will void the warranty on the card.
3.48When the system is in the default configuration,
all trunks are configured for M’MF signaling. If neces-
sary, some or all of the trunks can be reprogrammed fordial-pulse signaling through database programming.
Although both the LGC and the LSC can use dial-pulse
trunks, the pulse circuitry on the LGC is more sophisti-cated and may provide better performance in 
certainsit-
uations.
NOTE: Single-line sets generate their own MMF toneswhen dialing. If used on dial-pulse trunks, both the
DTMP tones generated by the phone and the dial-pulse
signals generated by the system are sent to the central
office, which may be a problem if the central office 
rec-
ognixes both. To avoid this problem, single-line sets
should be restricted to LCR only when using dial-pulse
trunks. Then, only the 
LCR-generated dial-pulse signals
will be sent to the central office.
3.49With loop start trunks, it is sometimes possiblefor the user to attempt to place an outgoing call and
instead be connected to an incoming call on the same
trunk. This unintended connection, called glare, is due
to the natural switching delay characteristics of the 
telco
equipment and the system. Previously, if the user did not
dial a valid outside number, the glare connection was
dropped. The software now allows the incoming call toremain connected, while still protecting against pos-
sible toll fraud. A new system-wide programmable op
tion, called Drop Incomplete Outgoing Calls, has been
added to the Miscellaneous System-Wide information
screen, as shown on page 5-67 in 
PROGlWMMING.
3.50The CO circuits are assigned hardware address
numbers according to the card’s slot in the equipment
cabinet and the location of the circuit on the card. For
example, when using the initial configuration (see para-
graph 
3.42), CO circuit 13.4 is the fourth circuit on the
13th card (an LGC) installed.351
When the system is in the default confi~ation,
the first four trunk keys on each keyset are assigned as
call keys for incoming call indication/access. 
Qhe AN-
SWER key may also be used to access incoming calls.)No individual trunk keys or trunk group keys are as-
signed. Key assignments can be designated in database
programming. Refer toPROG
RAMMING, page 5-44,
for more information.
3.52CO trunk groups may be assigned on a 
tenant-by-
tenant basis. Up to 47 CO trunk groups can be distrib-uted among the tenant 
grouPs. Refer to FEAWRES,
vage 4-15. for more information.
Page 2-14