ASL INTERCOM PS 29M User manual
PAGE 1
User Manual PS 29 M / Issue 2011 © ASL Intercom BV
CONTENT OF THIS USER MANUAL
1.0 GENERAL DESCRIPTION..................................................................................2
2.0 UNPACKING .........................................................................................................2
3.0 INSTALLATION .................................................................................................... 2
4.0 WARRANTY .......................................................................................................... 2
5.0 FRONT PANEL CONTROLS.............................................................................. 3
6.0 REAR PANEL CONNECTORS..........................................................................3
7.0 BOTTOM PANEL CONTROLS..........................................................................4
8.0 TECHNICAL SPECIFICATIONS PS 29 M.......................................................4
9.0 PART LINE, TECHNICAL CONCEPT...............................................................5
10.0 CABLING ...............................................................................................................5
11.0 BLOCK DIAGRAM PS 29 M..............................................................................6
12.0 SYSTEM CONFIGURATION ..............................................................................6
13.0 EARTHING CONCEPT........................................................................................7
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User Manual PS 29 M / Issue 2011 © ASL Intercom BV
1.0 GENERAL DESCRIPTION
The PS 29 M is a portable dual channel intercom
station. It is housed in a strong metal case
provided with a steel belt clip.
On the front panel the unit has, for each channel
A and B separately, a Volume (listen level)
control, a TALK push button and a CALL push
button , both with LED indicators.
On the rear panel are two XLR-3 connectors for
the intercom connection cables (two ‘party lines’)
and an XLR-4 headset connector.
As an option an XLR-5 headset connector can be
fitted, allowing to hear channel A at the left
headset can and channel B at the right headset
can.
On the bottom panel are side tone trimmers (one
for each channel), a buzzer volume trimmer and a
mic gain trimmer.
Special attention has been paid to the intelligibility
of speech. By applying low noise / high speed op-
amps, a speech presence filter and propriety high
power bridged headphone amplifiers,
communication is very comfortable even in
environments with a high level of background
noise.
The unique ASL call system provides both a
flashing red LED and a very distinctive sound
signal. A momentary push of the Call button
makes the red LED flash whilst holding the button
for 2 seconds activates the Call sound signal. The
volume of this sound signal (the buzzer) can be
adjusted at the front panel.
Fully electronic switching increases reliability and
allows for:
‘soft’ microphone On switching, latched or
momentary
Remote Mic Mute facility
2.0 UNPACKING
The shipping carton contains the PS 29 and this
user manual. If any are missing, contact your
dealer.
ASL has taken great care to ensure this product
reaches you in flawless condition.
After unpacking the unit please inspect for any
physical damage and retain the shipping carton
and relevant packing materials for use should the
unit need returning.
If any damage has occurred, please notify your
dealer immediately so that a written claim can be
initiated. Please also refer to the warranty section
of this manual.
3.0 INSTALLATION
This PS 29 M will form a part of an existing or
new intercom system. Connection to it is
straightforward. There are no separate power
connections or batteries to install as the
necessary DC voltages are derived from the
intercom master station or power supply, via the
intercom connection cables.
To connect the PS 29 M to the intercom system
use professional flexible microphone cable with 2
wires and 1 shield only.
The PS 29 M is fully protected against mis-wiring
(reverse power) or short circuit in the
interconnecting cables.
4.0 WARRANTY
This unit is warranted by ASL to the original end-
user purchaser against defects in workmanship
and materials in its manufacture for a period of 12
months from date of shipment to the end-user.
Faults arising from misuse, unauthorized
modifications or accidents are not covered by
this warranty.
If the unit is faulty it should be sent, in its original
packing, to the supplier or your local ASL dealer,
shipping costs prepaid. A note must be included
stating the fault(s) found and a copy of the
original suppliers invoice.
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User Manual PS 29 M / Issue 2011 © ASL Intercom BV
5.0 FRONT PANEL CONTROLS
1 VOLUME control knobs
These knobs are for adjusting the listen levels, for
each channel separately.
2 TALK buttons
These buttons allow talking to each channel
separately or to both channels simultaneously.
When a TALK button is switched on, its large
green LED is lit.
Momentary switching:
When a TALK button is pushed and held, the
microphone signal is sent to the referring intercom
channel until the button is released
Latched switching:
When a TALK button is pushed shortly it is
electronically latched and the microphone signal
is sent to the referring intercom channel. When
pushed again the TALK button switches Off.
Mic Mute when latched On:
After a so-called Mic Mute signal has been
received from a Pro Series master station or
power supply, the connection between
microphone and intercom channel is interrupted.
By pushing the TALK button, the connection is
restored and one can talk to the intercom channel
again.
3 CALL buttons
By pushing one of this buttons the Call function is
activated for the referring party line channel. With
a momentary push a Call signal is sent to all
intercom stations connected to that channel.
The Call LED’s on this PS 29 M and on all
stations connected to the same party line start
flashing. By pushing the Call button for 2 seconds
the Call Buzzers are activated, provided the
buzzers are not muted by a Buzzer Mute signal
received from a Pro Series master station or
power supply.
After the CALL button is released the LED’s
continue to flash for a further 2 seconds.
6.0 REAR PANEL CONNECTORS
4 LINE connector channel A
5 LINE connector channel B
These XLR-3 connectors are for connecting the
PS 29 M to intercom party lines.
Pin assignments:
Pin 1: 0V / ground shield
Pin 2: +30V DC power wire
Pin 3: audio wire
6 HEADSET connector
This XLR-4 connector is for connecting a headset
to the PS 29 M beltpack.
The impedance of the headset can must be
minimum 200 ohms; in case the headset has 2
cans in parallel, the impedance of each can must
be minimum 400 ohms.
Pin assignments:
Pin 1: shield mic. (GND)
Pin 2: mic. +
Pin 3: phones +
Pin 4: phones –
As an option, the PS 29 M can be fitted with a
XLR-5 headset connector, allowing to hear
channel A on the left headset can and channel B
on the right headset can.
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User Manual PS 29 M / Issue 2011 © ASL Intercom BV
7.0 BOTTOM PANEL CONTROLS
7 SIDE TONE trimmer channel A
8 SIDE TONE trimmer channel B
With the side tone trimmers #7 and #8 one
adjusts the level of your voice as you hear in your
headset, for each channel separately.
Adjustment procedure:
Turn trimmer fully clockwise
Switch the microphones of all (speaker)
stations connected to the referring party
line channel off
Activate the Talk function of the referring
channel
Turn up the listen volume of this channel
Speak into the headset microphone
Adjust the listen level by turning the side
tone trimmer
The operating area of the trimmers is between
fully clockwise and minimum level. Adjusting the
side tone does not affect the level of your voice
as heard by the other stations on the referring
party line channel.
9 BUZZER VOLUME trimmer
This trimmer adjusts the volume of the
internal buzzer (located behind the front
panel). The buzzer is activated when a CALL
button on this beltpack (or on any other
intercom station connected to one of both
party lines) is pushed longer than 2 seconds,
provided the buzzers are not muted by a
Buzzer Mute signal received from a Pro
Series master station or power supply.
10 MIC GAIN trimmer
This trimmer is to adjust the mic gain.
To increase the gain, turn clockwise and to
decrease the gain, turn counter clockwise.
8.0 TECHNICAL SPECIFICATIONS PS 29 M
Intercom System
Dynamic range: 80 dB (1 kHz, THD 1%)
Call signal: 2.8 mA
Call signal threshold (receive): +2.4V DC
Supply voltage: + 30V DC (12 –32V DC)
Power interrupt time (mic mute): 0.1 sec
Line Impedance: 350 Ω (1 kHz) / 2.2 kΩ (DC)
Audio level: nom. -18 dBu, max. +4 dBu
Side Tone
Rejection: 0 –30 dB adjustable
Buzzer
Max. SPL: 85 dBA
Mic pre-amp
Headset mic. impedance: 200 Ω
Gain: 35 –60 dB (adjustable internally)
Presence filter: +6 dB at 5 kHz
Frequency response: 200Hz - 15 kHz (-3 dB)
Power to electret mic: +9V DC
Headphone Driver Amps
Max. load: 200 Ω
Max output level:
monaural: 14 Vrms @ 200 Ω
binaural: 2x 10,6 Vrms @ 400 Ω
Max output power:
monaural: 1 Wrms @ 200 Ω
binaural: 2x 0.28 Wrms @ 400 Ω
PS 29 M Power Consumption
Current (at 30V DC):
30 mA quiescent,
45 mA signaling
170 mA at max. output + signaling
PS 29 M Dimensions & Weight
Width: 90 mm / Height: 48 mm (incl. clip)
Depth: 124 mm / Weight: 425 grams
0 dB defined as 775 mV into open circuit.
ASL reserves the right to alter specifications
without prior notice
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User Manual PS 29 M / Issue 2011 © ASL Intercom BV
9.0 PART LINE, TECHNICAL CONCEPT
User stations in an ASL intercom system are
interconnected via one or several ‘party lines’
A party line offers two way (‘full’ duplex’)
communication and consists of standard microphone
(multi-pair) cable. One wire is used for the audio signal
and one wire for the DC power. The screen of the
microphone cable functions as earth/return.
Current drive is used for signal transfer.
Each intercom station utilizes a current amplifier to
amplify the microphone signal. That signal is put on
the common audio line.
Due to the constant line impedance, a signal voltage is
developed which can be further amplified and sent to
headphones or loudspeakers.
(the line impedance is situated in the power supply
between XLR pin 3 and pin 1)
This principle has the following advantages:
The use of a single audio line allows several
intercom stations to talk and listen
simultaneously
Due to the high bridging impedance offered by
each intercom station. The number of stations
on the party line has no influence on the level
of the communications audio signal.
Power and audio to the intercom stations use
the same cable
Also the Call signal is sent as a current, on the audio
wire. It develops a DC potential over the line
impedance which is sensed by each intercom station
and interpreted as a Call signal.
10.0 CABLING
The intercom lines (the ‘party lines’) are of the shielded two-conductor microphone cable type.
The intercom line connectors are of the XLR-3 type. Audio and Call signals are on pin 3. DC power is on pin 2.
Pin 1 is connected to the shield of the cable which functions as the common return for audio and power.
The audio signal is transferred in an unbalanced way (see Party Line, Technical Concept).
To avoid earth loops (hum), the possible effect of electromagnetic fields and to minimize power loss , certain rules
have to be obeyed when installing the cabling of an intercom system:
Use high quality cable
Use high quality microphone cable only (shielded two
conductor cable, minimum 2x 0.30 mm2). In case
multi-pair cable is used, there should be an overall
shield and each pair should consist of two conductors
(minimum 2x 0.15 mm2) with separate shield.
Use flexible cable
Use flexible single and multi-pair microphone cable
instead of cable with solid cores, especially when the
cable is subjected to bending during operation or
installation.
Cable screens to XLR pin 1
The screen of each separate microphone cable and/or
the screen of each single pair in a multi-pair cable,
should be connected to pin 1 of each XLR-3
connector. Do not connect these screens to the metal
housing of ASL units or XLR-3 wall boxes).
See Earthing Concept.
Connect cable trunks, connection boxes and
overall multi-pair cable screens to clean earth
Metal cable trunks, metal connection boxes and overall
multi-pair cable screens should be interconnected and,
at one point (the 'central earth point') in the intercom
network only, be connected to a clean earth or a safety
earth (see Earthing Concept).
Keep metal connection boxes and trunks isolated
from other metal parts
Metal trunks or pipes for intercom cables and metal
connection boxes should be mounted in such a way
that they are isolated from any other metal housing or
construction parts.
Keep cables parallel as much as possible
When two (multi channel) units in a network are
connected by more than one cable, make sure that
these cables are parallel to each other over the whole
distance between those units. When using multi-pair
cable, parallelism is ensured in the best possible way.
Avoid closed loops
Always avoid that intercom cables are making a loop.
So-called 'ring intercom' should not physically be
cabled as a ring.
Keep cables away from electromagnetic sources
Keep intercom cables away from high energy cables,
e.g. 115/230/400V mains power or dimmer controlled
feeds for spotlights. Intercom cables should cross high
energy cables at an angle of 90º only. Intercom cables
should never be in the same trunks as energy cables.
Place power supply in a central position
In case of a system powered by a separate power
supply: In order to diminish power losses, place the
power supply as close as possible to where most
power consumption occurs, in other words most user
stations are placed.
Connect ASL powered units to a 'clean' mains
outlet
Master stations or power supplies should be
connected to the mains outlet with a clean earth. Other
audio equipment may be connected to this mains
outlet, but avoid using mains outlets which also power
dimmer controlled lighting systems.
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User Manual PS 29 M / Issue 2011 © ASL Intercom BV
11.0 BLOCK DIAGRAM PS 29 M
12.0 SYSTEM CONFIGURATION
PAGE 7
User Manual PS 29 M / Issue 2011 © ASL Intercom BV
13.0 EARTHING CONCEPT
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