ASL INTERCOM BS 217 User manual

December 2016
V1.0
BS 217
DUAL CHANNEL MASTER STATION
User Manual

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Table of contents
1.0!SAFETY*INSTRUCTIONS*..............................................................................................*3!
2.0!GENERAL*DESCRIPTION*BS*181*..................................................................................*4!
3.0!MECHANICAL*INSTALLATION*.....................................................................................*5!
4.0!MAINS*POWER*&*SAFETY*EARTH*...............................................................................*6!
5.0!FRONT*PANEL*CONTROLS*&*CONNECTOR*..................................................................*7!
6.0!REAR*PANEL*CONTROLS*&*CONNECTORS*..................................................................*9!
7.0!TECHNICAL*SPECIFICATIONS*....................................................................................*10!
8.0!BS*217*BLOCK*DIAGRAM*.........................................................................................*11!
9.0!PARTY*LINE,*TECHNICAL*CONCEPT*...........................................................................*12!
10.0!CABLING*.................................................................................................................*12!
11.0!POSSIBLE*SYSTEM*CONFIGURATION*........................................................................*14!
12.0!EARTHING*CONCEPT*...............................................................................................*15!

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1.0 SAFETY INSTRUCTIONS
Please always follow these instructions to help ensure against injury to yourself
and/or damage to the system
1. Read all safety and operating instructions before you operate the apparatus.
2. Retain all safety and operating instructions for future reference.
3. Heed all warnings on the apparatus and in the safety and operating instructions
and follow all installation and use instructions.
4. Follow all installation, operating and use instructions
5. Unplug the apparatus from the AC power outlet before cleaning. Use only a
damp cloth for cleaning the exterior of the apparatus.
6. Do not use accessories or attachments not recommended by the manufacturer,
as they may cause hazards and void the warranty.
7. Do not operate this apparatus in high humidity areas or expose it to water or
moisture.
8. Do not place the apparatus on an unstable cart, stand, tripod, bracket or table.
The apparatus may fall, causing serious personal injury and damage to the appa-
ratus.
9. Do not block or cover any openings in the apparatus. These are provided for ven-
tilation and protection from overheating. Never place the apparatus near any
heat sources such as radiators, heat registers, stoves, or other apparatus (includ-
ing amplifiers) that produce heat. Do not place the apparatus in an enclosure
such as a cabinet without proper ventilation.
10. Operate the apparatus using only the type of power source indicated on the
marking label. Unplug the apparatus’ power cord by gripping the power plug, not
the cord.
11. Insert the plug properly. Do not defeat the safety purpose of the polarized or
grounding-type plug. An American polarized AC line plug has two blades with one

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wider than the other. This plug will fit only one way into the power outlet. This is
a safety feature. If you are unable to insert the plug fully into the outlet, try re-
versing the plug. If the plug still fails to fit, contact an electrician to replace the
obsolete outlet. A grounding type plug has two blades and a third grounding
prong. The wide blade or the third prong are provided for your safety. If the pro-
vided plug does not fit into your outlet, consult an electrician to replace the obso-
lete outlet.
12. Route power supply cords so that they are not likely to be walked on or pinched
by items placed upon or against them. Pay particular attention to cords at plugs,
convenience receptacles, and the point where they exit from the apparatus.
13. Do not overload wall outlets or extension cords, as this can result in a risk of fire
or electrical shock.
14. Unplug this apparatus during lightning storms or when unused for long periods
of time.
15. Never insert objects of any kind into the apparatus through openings, as the ob-
jects may touch Dangerous voltage points or short out parts. This could cause
fire or electrical shock.
16. Refer all servicing to qualified service personnel. Servicing is required when the
apparatus has been damaged in any way, such as when the power-supply cord or
plug is damaged, liquid has been spilled or objects have fallen into the apparatus,
the apparatus has been exposed to rain or moisture, does not operate normally,
or has been dropped.
2.0 GENERAL DESCRIPTION BS 181
The BS 217 (19”/1RU) is designed to be a dual channel master station in an ASL intercom
system. Master station and remote stations are interconnected by standard microphone
cable.
The built-in power supply can safely drive up to 15 Basic Series beltpacks operating at full
power.

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The power supply is fully protected against wiring mistakes (reverse power), short circuit
or dangerous thermal condition. Should one of these conditions occur, the unit shuts
down. Once the fault condition has been removed, the unit resets automatically and
power is restored.
Each channel has a Volume control, a TALK and a CALL button with LED indicators.
With side tone trimmers one adjusts the listen level of one’s voice in one’s headset.
With a headset connected to the XLR-4 headset connector one can talk and listen to each
channel separately or to both channels simultaneously.
The unique ASL Call system provides both a flashing red LED and a very distinctive sound
signal. A slight touch of the CALL button makes the call LED flash, whilst holding the button
for 2 seconds the call sound signal is activated.
An Aux input connector with Ground Lift switch at the rear panel allows injecting external
line level audio signals into the intercom lines.
Special attention has been paid to the intelligibility of speech. By applying low noise/high
speed circuitry, a speech presence filter and a specially designed headphone amplifier,
communication is very comfortable even in environments with high background noise
levels.
3.0 MECHANICAL INSTALLATION
For the BS 217 a vertical rack space of 1RU (1.75”, 44mm) is required. It is not necessary
to provide rear support by extra bracing or shelving. Adequate ventilation must be pro-
vided by allowing sufficient space around the sides and rear of the unit to ensure free
circulation of air. Forced cooling is not required.
The power supply regulator is mounted on the rear of the unit; after a period of time it
will feel hot to the touch. This is quite normal, and should be no cause for alarm.

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4.0 MAINS POWER & SAFETY EARTH
The BS 217 may be connected to a mains power outlet which provides 100 – 240 V AC, 50-
60 Hz and at least 60 watts. The outlet should have a clean earth. Avoid using mains power
outlets which also power dimmer controlled lighting equipment.
The wires in the mains lead are color coded in accordance with the following code:
Green/ yellow: Earth / safety ground
Blue: Neutral
Brown: Live
In case the colors of the wires in the mains lead do not correspond with the colored mark-
ings identifying the terminals in your plug, proceed as follows:
• The wire which is colored green-and-yellow must be connected to the terminal in
the plug which is marked with the letter "E", or by the earth symbol or is colored
green.
• The wire which is colored blue must be connected to the terminal which is marked
with the letter "N" or is colored black.
• The wire which is colored brown must be connected to the terminal which is
marked with the letter "L" or is colored red.
Safety Earth
The green-and-yellow wire of the mains cord must always be connected to the elec-
trical installation safety earth or ground!
This is essential for personal safety as well as for proper operation of the BS 217 and the
other connected stations. The green/yellow wire is in the BS 217 connected to all exposed
metal surfaces. Any rack framework into which this unit might be mounted is assumed to
be connected to the same grounding circuit.

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5.0 FRONT PANEL CONTROLS & CONNECTOR
1 POWER ON/OFF switch
Mains power push button to switch the internal power supply on or off.
2 MAINS POWER LED
This LED illuminates if line power is supplied by the internal power supply.
3a BUZZER VOLUME trimmer
To adjust the volume of the buzzer.
3b BUZZER
This buzzer indicates an incoming or outgoing call. It is activated by pushing a
CALL button on this station or a CALL button on any other station for longer than
two seconds. The volume of the buzzer may be adjusted with the buzzer volume
control.
4 VOLUME knobs for channel A & B
To adjust the listen level for the headset. Each channel has to be adjusted sepa-
rately.
5 SIDE TONE trimmers channel A & B
To adjust the level of one’s voice as heard in one’s headset.
Adjustment procedure (for each channel separately):
• set the trimmer in start position: fully clockwise
• switch off the microphones of all connected stations
• push the TALK button of the channel
• turn up the volume of the channel
• speak into the headset microphone
• adjust the listen level by turning the side tone trimmer of the channel.
The trimmer operating area is between fully clockwise and minimum level. Adjust-
ing the side tone does not affect the level of your voice as heard by other stations.

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6 TALK buttons + LEDs channel A & B
These buttons allow the user to talk to each channel separately or to both channels
simultaneously. The large green LED’s indicate if the talk function is activated.
7 CALL buttons + LEDs channel A & B
A Call button activates the Call system.
By a momentary push a Call signal is sent to all stations connected to the referring
intercom channel. The Call LED on this station and on all to the channel connected
stations starts flashing. Pushing and holding a Call button for 2 seconds activates
the call buzzer in all stations. After the CALL button is released the Call LED’s con-
tinue to flash for a further 2 seconds.
8 AUX VOLUME controls A & B
To adjust the level of the Aux input signal to each of the two intercom lines.
9 MIC GAIN trimmer
To adjust the input gain of the headset microphone signal.
10 HEADSET connector
A XLR-4 connector to connect a headset.
The can impedance must be minimum 200 ohms. The headset microphone may
be of the dynamic or electret type.
Pin assignments:
Pin 1: shield mic. (GND)
Pin 2: mic. +
Pin 3: phones +
Pin 4: phones –

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6.0 REAR PANEL CONTROLS & CONNECTORS
11 INTERCOM LINE connectors for Channels A & B
These XLR-3 type connectors are for connecting remote stations, using standard
microphone cable. There are 2 connectors for channel A and 2 connectors for
channel B.
Pin assignments:
Pin 1: 0V / ground shield
Pin 2: +30V DC power wire
Pin 3: audio wire
12 AUX INPUT connector + Ground Lift
This input is electronically balanced and accepts line level audio signals
Pin assignments :
Pin 1: 0V / ground
Pin 2: signal +
Pin 3: signal –
13 FUSE HOLDER
The fuse protects the BS 216 against severe internal damage, in case of malfunc-
tion in the power section.
Before replacing a fuse the mains cord must be disconnected from the mains
outlet.
14 MAINS INLET
IEC Mains connector

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7.0 TECHNICAL SPECIFICATIONS
System Specifications
• dynamic range: 80 dB (1 kHz, THD < 1%)
• frequency response: 200 Hz – 15 kHz (-3 dB)
• call signal (send): 2.8 mA
• call signal threshold (receive): +2.4 V DC
• operating voltage: 24 - 32 V DC
Intercom Line
• Impedance: 350 Ω (1 kHz), 2.2 kΩ (DC)
• Audio level: nom. -18 dBu, max. 0 dBu
Switch Mode Power Supply
• Mains voltage range: 100 -240 V AC, 50-60 Hz
• DC output voltage: +30 V DC (+/-5%)
• Max. output power: 45 watts
Headphone Driver Amp
• Max. output level: 11.6 Vrms (at 200 Ω)
• Max. output power: 0.7 Wrms (at 200 Ω)
Mic Pre-amp
• Gain: 40 - 60 dB
• Presence filter: +6 dB @ 5 kHz
• Power to electret mic: 9 V DC
Side Tone
• Rejection: 0 - 30 dB adjustable
Buzzer
• Max. SPL: 90 dBA @ 0.1m
Aux Input
• Input Impedance: 33 kΩ
• Nominal Input Level: 0 dBu
• Max. Input Level: +22 dBu