BT ESCORT
PXML No. 102
APPROVAL No. NS/1000/3/E/450427
USER GUIDE
The Escort Call Connect System comprises a wall mounted Central Control Unit (CCU) and
extension telephones with associated key-modules individually cabled to the CCU. The CCU
contains a transformer type power unit, line termination strips, switching relays and
electronic control circuitry, it is similar to the TMC KBX 3
& KBX 6
CCU but is covered by a
separate approval and PXML (PXML 102).
The system is designed to accommodate up to 2 incoming trunks and up to 6 extensions.
Incoming trunks may be Exchange Lines or PBX Extensions as detailed under 'Approval
Status'.
Press buttons on the key-modules enable direct press button access to exchange lines and
other extensions, an additional button (Mode button) is also provided to facilitate
customer programmable facilities. LEDS are provided next to the exchange line buttons to
indicate status of exchange line. Key modules may be table or wall mounted.
The signalling system between the key-module and CCU is based on DC resistance conditions
applied to the signalling leads when the key-module buttons are pressed.
Optionally, extensions 1 and 3 may be used as (2 wire) extensions with restricted
facilities.
External extensions are not available.
The system has only one intercom circuit, which is non-secret.
Introduced around 1986
DIMENSIONS
CCU measures 320mm x 225mm x 85mm, approx. weight 4kg.
Key-modules measure 180mm x 155mm x 40mm, approx. weight 270g
Made by TMC Limited
CCU shown on the right
APPROVAL STATUS
Approved for indirect connection to the PSTN (loop disconnect or MF4 signalling
depending on extension telephones fitted) by working as a (List 'A') subsidiary system
connected to a (List 'C') PBX.
The system supports Earth loop or 'C wire supervision' recall. Timed-break recall
facilities may be made available by providing 'timed-break recall' telephones on
extensions.
Approved telephones (as of May 1986)
Tribune
Statesman family
Ambassador family
Viscount family
Venue 24
Facilityphone 300
Tonto
Sherwood
SOFTWARE
Approved software levels for Escort are:-
TMC1215B*
TMC1216* or TMC1216A*
marked on Custom I/Cs in CCU.
The system has a nominal power consumption of 30 watts and does not require a mains earth.
There is no provision for standby power.
GENERAL
Access to cable terminations and mains fuse is gained by loosening the two large screws on
the cover this will enable the lower half of the cover to slide down for removal. Mains
supply must be disconnected before removing the mains cable terminal cover or mains fuse.
The CCU is wall mounted by a flush fitting bracket and may be removed (when cabling has
been disconnected) by removing the cross-headed securing screw adjacent to the
configuration switches and lifting off.
It is not a maintenance responsibility to program Escort extensions. If extension
programming has been lost due to a fault condition, customers should be advised to
reprogram extensions when the fault has been cleared. If requested, maintenance engineers
should offer basic assistance to enable customers to programme their facilities.
When maintenance exchanging the CCU ensure that the internal switch settings
(SW1 - 4) are
set the same as in the unit it replaces. These switches are not customer accessible.
These switches are initially set by the manufacturer to OFF and the facilities
afforded by them are only active when in the ON position.
ESCORT FEATURES/FACILITIES
NOTES ON FEATURES AND FACILITIES
CCU Switch settings
|
SWITCH |
FUNCTION |
| 1 | Two wire working on extn 1 |
| 2 | Two wire working on extn 2 |
| 3 | C wire signalling |
| 4 | Exclusive line facility on extn 4 |
| CCU | CABLE WIRING COLOURS | LJU -/1A |
| A | WHITE/ BLUE | 5 |
| B | BLUE/WHITE | 2 |
| C | WHITE/ORANGE | 4 |
| D | GREEN/WHITE | 1 |
| E | WHITE/GREEN | 6 |
Mains Fail
| Line | Extension |
| 1 | 1 |
| 2 | 4 |
The module extension keys are numbered numerically from left to right
omitting their own extension number.
e.g. Extension 2 would read: 1 - 3 - 4 - 5 - 6.
WARRANTY
New units, either those supplied with the system or as maintenance spares carried a 24
month warranty from date of manufacture. The year and week of manufacture form the first
four digits of the eleven digit serial number marked on the base of the CCU or key module.
PARTS
| DESCRIPTION | BT Item code |
| Escort CCU | 870197 |
| Escort Key Module | 870198 |
| Fuse 36A/0.5 | 310755 |
LINE TESTING
Idle - Normal capacitance loop.
Seized - Normal Tele loop when through to an extension.
Held - 260 ohm loop.
ADDITIONAL INFORMATION
The Escort is approved as a non-earthed CRA and hence earth leads must not be
connected to the E tags of the exchange line terminal blocks.
Not recommended for use on host systems that give continuous ringing as Escort cannot trip
ringing during a ringing period.
With the lower cover removed, the upper cover may be removed by sliding outwards the two
small rectangular latches (one each side at the lower corners of the upper cover) and then
lifting the cover away. The upper cover needs to be removed to check PXML software and
hardware markings and date of manufacturer.
The ringing generator of the Escort System is designed to ring all six extension ports
simultaneously provided that the Ringer Equivalent Number (REN) on each port does not
exceed 2.0.
Extension bells can therefore be fitted at extension ports where the telephone has a REN
of one or less.
Extension bells should be hardwired to terminals 3 and 5 on the extension phone socket.
Extension bells approved for use with the Escort system are:-
Bell 59D (High Impedance ringing device)
Bell 80D (incorporated in Bell Set 50C)
Fuses
Fuses used on this system are BT type:- 36A/0.25
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