TOA Electronics VS-900 - Manual (Page 10)

VS-900 Architects and Engineering Specifications v1.0
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The Audio Function Card shall be the TOA VS-900AF.
2.4.8 TIE-LINE INTERFACE CARD
The Tie-Line Card shall be powered by the Exchange Mainframe and allow interconnection of up
to sixteen exchanges in a multi-drop or “bussed” configuration. Systems requiring a closed loop
among multiple exchanges shall not be acceptable. User-dialed key sequences required for inter-
exchange calling and paging shall be identical to those used for intra-exchange calling and
paging. The Tie-Line Interface shall provide four voice links, 0 dBu, balanced two, twisted pair
cable each and data control, RS-485, shielded, twisted pair cable, shared among the tie-lined
exchanges. The maximum service distance (total bus length) shall be as follows: #20 AWG:
4,921 ft./0.93 mile (1.5 km); #22 AWG: 3,281 ft./0.62 mile (1 km); #24 AWG: 1,969 ft./0.37 mile
(0.6 km). It shall be possible to convert the voice paths to fixed-direction (send and receive) to
accommodate standard audio media converters and the Site Connector Tie-Line Interface.
The Tie Line Interface Card shall be the TOA VS-900TI.
2.4.9 SITE CONNECTOR TIE-LINE INTERFACE
The Site Connector Tie-Line Interface shall allow the interconnection of multiple exchanges with
standard audio fiber interfaces or other media converters by combining up to four voice links from
two Exchange Mainframe Tie-Line Interface Cards. The Site Connector Tie-Line Interface shall
require an external 20 VAC Power Supply Unit (see section 2.4.2) and occupy (2) EIA 19” rack
spaces.
The Site Connector Tie-line Interface shall be the TOA VS-900SC.
2.5 PERIPHERAL COMPONENTS
2.5.1 DIRECT SELECT INTERFACE
The Direct Select Interface (DSI) Card shall connect between each Master Station and
associated Master Station Line Card port and support up to thirty-two (32) Direct Select I/O
(DSIO) Cards. The maximum number of DSI Cards shall be four (4) per exchange and (64) per
system (16 tie-lined exchanges). The DSI Card shall require an external 24 VDC/1 A power
supply.
The DSI Card shall provide headset, microphone input, speaker output and key inputs. A Master
Station shall not be required to utilize the DSI Card’s headset, microphone input, speaker output
and key inputs.
The headset interface shall have adjustable microphone sensitivity from -75 to -65 dBV,
defeatable 5 VDC phantom power and support speaker impedance of 200 to 400 ohms with
adjustable speaker volume. A detection jack contact input, 5 VDC/10 mA, contact resistance less
than 10 ohms shall be available to support headset activation.
The microphone input shall have adjustable microphone sensitivity from -75 to -65 dBV with a
defeatable 5 VDC phantom power supply. The speaker output shall provide one Watt power
output into an eight ohm speaker load with adjustable speaker volume.
The function key inputs shall allow contact closure activation of the equivalent to the Master
Station [C], [PTT], and [Transfer] key functions as well as a [Test] key input for activating and
testing all of the connected DSIO Card outputs. The key inputs shall be activated with a dry
contact switch closure with a rating of 5 VDC/0.5 mA and contact resistance of less than 50
ohms. An In-use Indication Output shall be available general purpose control, open collector type,
24 VDC/100 mA.