ND-20292
CHAPTER 2
APRIL, 1990
rr 1
ETU
COI-E( )
ESI-EA/B
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CIRCUITS
CALCULATION
MAXIMUM ETUs
PER ETU PER SYSTEM
4 Divide the number of CO/PBX lines being used by 4. (Note 1) 10 (Note 7)
4 Divide the number of Multiline Terminals, CO Add-On Modules,
and DSS/BLF Consoles being used by 4. (Note 2) 20 (Note 4)
SLI-Em
MFR-EA
CNF-E
ECR-E
4 Divide the number of Single Line Telephones and/or Modems being
used by 4. (Note 3) 19 (Note 4)
2 See Table 200-l. 4
1 The number of Conference circuits being used. 4
When installing multiple zones of External Page, Chime, BGM to
10 Multiline Terminals, or Delay Announcement Unit, and/or tone 1
ringers, an ECR-E ETU is required.
VMI-E When connecting Voice Mail system, Single Line Telephone, and/or
4 Dictation equipment, and/or Auto Attendant, VMI-E ETU is 2 (Notes 4 5
required. 6, & 8) ’ ’
TLI-E 2 Divide the number of DID and/or Dial Pulse E&M Tie Lines being
used by 2. (Note 1) 20 (Note 7)
TLI-EB 2 Divide the number of DTMF/Dial Pulse E&M Tie Lines being used
by 2. (Note 1) 20 (Note 7)
v . 4 rn.. *,. . 1, 1 I., . 2, .a.. 1 , ,
,
vote 1: lr tne result is not a wnole numner, rouna it up to tne next nigher wnole number.
Note 2: A Multiline Terminal, with DPA-E Unit (Off-hook Announcement Adaptor) or DTA-E Unit (Data
Switching Adaptor) installed, requires an ESI-EB ETU, divide the number of those Multiline ’
Terminals installed by 4. If the result is not a whole number, round it up to the next higher whole i
number. This is the quantity of ESI-EB ETUs required.
If some ports are still available on an ESI-EB, subtract the number of available ports on the ESI-EB-
ETU from the number of Multiline Terminals being used w/o DPA-E or DTA-E Units. Then, divide
the number by 4. If the result is not a whole number, round it up to the next higher whole number.
This is the quantity of ESI-EA ETUs required.
Note 3: It is necessary for an SLT with Message Wait lamp and/or Power Failure Transfer to be supported by
an SLI-EB ETU. Divide the number of modems (used for Modem Pooling) and/or Single Line
Telephones with Message Wait lamp by 4. If the result is not a whole number, round it up to the next
higher whole number. This is the quantity of SLI-EB ETUs required.
If some ports are still available on an SLI-EB ETU, subtract the number of available ports on the SLI-
EB ETU from the number of Single Line Telephones w/o Message Wait lamp. Then divide the
resulting number by 4. If the result is not a whole number, round it up to the next whole number. This
is the quantity of SLI- EA ETUs required.
Note 4: Combined total of ESI-EA, ESI-EB, SLI-EA, SLI-EB and VMI-E ETUs cannot exceed 20. A maximum
of 80 stations, of which, a maximum of six can be EDE-30-( ) consoles.
Note 5: When a Voice Mail system is connected to the Electra MarkII, MFR-EA ETU and RSG-E Unit may be
required, depending on the model of Voice Mail system.
Note 6: When Modem Pooling and/or a Voice Mail system is connected to the Electra MarkII, an RSG-E Unit
and MFR-EA Unit may be required.
Note 7: Combined total of CO/PBX, and E&M Tie lines cannot exceed 40. COI-EB ETU’s support Centrex ring
patterns. .’ /
Note 8: A CPU-EC4 (or higher revision level) ETU is required to support two VMI-E ETUs, otherwise, only ’ 1
one VMI-ETU may be installed.
200-4