Austdac ABMA4 User manual

Title
I.S. INTERCOM
TYPE ABMA4
USER MANUAL
Document Number
20-278-12
Issue
05

I.S. INTERCOM 20-278-12
TYPE ABMA4 USER MANUAL 2 OF 21 Issue: 05
05 Address and Logo Update 2017-03-24 CW CW PC
04 Images and Contact Details Update 2015-06-09 NK NK MC
03 Time to sleep from Menu, Speak and
PSA activity has changed. 2007-03-27 CG CG PB’
Issue Details Date Drawn Designed Approved
Austdac Pty Ltd
Unit 1 / 42 Carrington Road
Castle Hill NSW 2154
Australia
PO Box 6486
Baulkham Hills Business Centre
NSW 2153
Australia
Phone: + 61 2 8851 5000
Fax: + 61 2 8851 5001
Website: www.austdac.com.au
Copyright 2017
This document remains the property of Austdac Pty. Ltd. It is subject to its recall and must not be reproduced
in part or whole or its contents divulged to third parties without prior written approval from Austdac Pty Ltd.
TABLE OF CONTENTS
TABLE OF CONTENTS..................................................................................................................................... 2
PHOTOGRAPHS............................................................................................................................................... 3
FIGURES........................................................................................................................................................... 3
TABLES............................................................................................................................................................. 3
1. GENERAL DESCRIPTION..................................................................................................................... 4
2. OPERATIONAL DESCRIPTION............................................................................................................. 6
3. BACKGROUND OPERATIONS ............................................................................................................. 6
1. Detection of PSA .............................................................................................................................. 6
2. Detection of Speech for Speaker Mute Control................................................................................ 7
3. Detection of Low R-Line Voltage...................................................................................................... 7
4. Pressing of SPEAK key.................................................................................................................... 7
5. Switching between Sleep and Deep Sleep modes........................................................................... 7
6. Watchdog kicks................................................................................................................................. 8
4. GENERIC DISPLAY DECRIPTION........................................................................................................ 8
Battery and Speaker Health Icons........................................................................................................ 8
PSA Health Interface Icons .................................................................................................................. 9
Text Box................................................................................................................................................ 9
5. CONFIGURATION MENU DESCRIPTION ............................................................................................ 9
Battery Menu ...................................................................................................................................... 10
Comms Line........................................................................................................................................ 10
Setting................................................................................................................................................. 10

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1. Volume Option................................................................................................................................ 11
2. Test Speakers................................................................................................................................. 11
3. Mute Level Menu............................................................................................................................ 12
4. About Menu .................................................................................................................................... 13
6. INSTALLATION AND CONNECTIONS................................................................................................ 14
Cable Shielding................................................................................................................................... 14
7. SYSTEM TEST AND FAULT FINDING................................................................................................ 15
Flow Diagram Description .................................................................................................................. 15
Fault Analysis ..................................................................................................................................... 15
8. HANDSET............................................................................................................................................. 21
9. CERTIFICATION .................................................................................................................................. 21
PHOTOGRAPHS
Photograph 1: Intercom type ABMA4 front view. .............................................................................................. 4
Photograph 2: Intercom type ABMA4 rear view ................................................................................................ 5
Photograph 3: Battery type 5/NH/1-N side view................................................................................................ 5
Photograph 4: ABAM4 Menu Keys.................................................................................................................... 6
FIGURES
Figure 1: Confirmed PSA Loop.......................................................................................................................... 7
Figure 2: LCD Generic View.............................................................................................................................. 8
Figure 3: Menu Options..................................................................................................................................... 9
Figure 4: Battery Menu View ........................................................................................................................... 10
Figure 5: Comms Line View............................................................................................................................. 10
Figure 6: Setting menu .................................................................................................................................... 10
Figure 7: Volume Menu View .......................................................................................................................... 11
Figure 8: Test Speaker Menu View................................................................................................................. 11
Figure 9: Test Speakers Completed View....................................................................................................... 12
Figure 10: Mute Level Menu............................................................................................................................ 12
Figure 11: Password Access screen............................................................................................................... 13
Figure 12: Set Mute Level Low........................................................................................................................ 13
Figure 13: Set Mute Level Medium.................................................................................................................. 13
Figure 14: About Menu logo ............................................................................................................................ 13
Figure 15: About Menu Information................................................................................................................. 14
Figure 16: Simplified Un-Shielded Circuit........................................................................................................ 14
Figure 17: TEU Fault Example ........................................................................................................................ 16
Figure 18: V-Line break at the front................................................................................................................. 16
Figure 19: V-Line break in the middle.............................................................................................................. 17
Figure 20: V-Line break at the end.................................................................................................................. 17
Figure 21: S-Line break at the front................................................................................................................. 18
Figure 22: S-Line break in the middle.............................................................................................................. 19
Figure 23: S-Line break at the end.................................................................................................................. 19
Figure 24: R-Line break at the front................................................................................................................. 20
Figure 25: R-Line break in middle ................................................................................................................... 20
Figure 26: R-Line break at end...................................................................................................................... 211
TABLES
Table 1: Top Left Generic Icons ........................................................................................................................ 8
Table 2: Top Right Generic Icons...................................................................................................................... 9

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1. GENERAL DESCRIPTION
This document should be read in conjunction with 20-079-12 user’s manual. The intercom type ABMA4
provides the audio communications and pre-start alarm sounding facilities of the PSACS1 system. Intercoms
are distributed along the conveyor at fixed distances apart to provide complete sound coverage along the
conveyor. During a pre-start sequence the intercom sounds the pre-start alarm through its two sideways
facing speakers. These same speakers and the front panel mounted microphone are used to carry out a half
duplex voice conversation with other intercoms on the conveyor or a surface located BMA exchange
operator. Photograph 4 below shows the front panel of a type ABMA4 intercom.
Photograph 1: Intercom type ABMA4 front view.
The intercom type ABMA4 has seven front panel mounted push buttons, a front panel microphone, an LCD
display and two side-mounted speakers to provide the voice communications interface for staff working
along the conveyor belt. The LCD display allows the operator to view operational and maintenance
information about the intercom and the PSACS1 system.
A conversation with another worker along the conveyor belt can be initiated by pressing the local call button
once or several times. The local call button is used to signal or attract the attention of workers along the
conveyor. The local call button can be pressed and released to sound a series of beeps along the conveyor.
The patterns and meaning of these beeps can be used to transmit messages to others along the belt.
The call exchange button is pressed to attract the attention of the BMA exchange operator at the surface.
Once the operator has acknowledged the call further instructions, such as patching requests, can be given
from the intercom.
The voice communications of the PSACS1 system is a half duplex i.e. only one party can speak at a time.
The speak button of the intercom must be pressed whenever the user wishes to speak. It is important to get
used to pressing the speak button just before speaking and releasing it just after finishing speaking. Failure
to control the speak button correctly will result in the beginning or end of a statement being cut off.

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Photograph 2: Intercom type ABMA4 rear view
The above photograph shows the rear of the ABMA4 intercom with its battery removed. In the LO position
the battery charge current is 11mA and 22mA in the HI position. Refer to the system drawing for the correct
charge rate for your intercoms. Generally, the HI position is used in systems with short powered segments
and fewer intercoms, the LO position is used in long powered segments with more intercoms.
Photograph 3: Battery type 5/NH/1-N side view

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2. OPERATIONAL DESCRIPTION
The intercom type ABMA4 has seven front panel mounted push buttons. The main visual difference between
the ABMA4 and other I.S. Intercoms is that the ABMA4 has a LCD graphical display and addition of ‘Menu’,
‘Enter’, ‘Up’ and ‘Down’ keys or push buttons (‘keys’ will be used interchangeably with ‘push buttons’
throughout this document). Another difference is that the ABMA4 has a more powerful micro controller that
allows graphical representation of the state of cable, PSA controller and internal operation of ABMA4.
Photograph 4: ABAM4 Menu Keys
There are three main areas showing the working of ABMA4:
1. Background Operations
2. LCD Generic Graphical Display Mode
3. Configuration and Status Mode
3. BACKGROUND OPERATIONS
These tasks happen no matter what state the graphical display is at. These are as follows:
1. Detection of PSA (Pre-Start Alarm)
2. Detection of Speech for Speaker Mute Control
3. Detection of Low R-Line Voltage
4. Pressing of SPEAK key
5. Switching between Sleep and Deep Sleep modes
6. Watchdog kicks
1. Detection of PSA
The unit continuously detects for a PSA paired tone signal on both the V-line and S-line. The V-line is the
audio signal from the PSA Controller and the S-line is a return signal from end termination unit or Tail End
Unit (TEU). TEU (such as TEU100) returns the signal with the tone frequency divided by eight. The following
frequency pairs are detected on the V-line:
1. 1500Hz alternating with 1800Hz @ 0.4mS cadence
2. 1400Hz alternating with 1700Hz @ 0.2mS cadence
3. 1300Hz alternating with 1900Hz @ 0.8mS cadence
The AMBA4 units check for cadence as well as frequency tones pair for a PSA confirmation. The cadence
period need to be present for at least three quarters of the cadence for each frequency pairs for detection.
For example, a 1500Hz and 1700Hz is an in-correct pair. The frequency and cadence ensures a false PSA

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trigger does not occur say in PTT action when someone or a machine is whistling or creating noise near
these PSA frequencies.
On detection of the PSA, the unit will wake up the display if asleep and show flashing ticks (√) in a PSA loop.
The flashing indicates that the PSA is occurring.
Figure 1: Confirmed PSA Loop
If the ABMA4 sees only an S-line return signal then the V-line will have a cross (X) in the PSA loop and tick
(√) in the S-line (see table 2 for more explanation below). The flashing of the ticks (√) continue for a small
period after the PSA tone has disappeared to ensure the user sees any PSA changes.
When a PSA event occurs, the Speakers output will go to maximum volume on the first tone of the frequency
pair immediately that it detects a correct PSA frequency. This is so the user has the maximum opportunity to
hear PSA tone at the earliest possible time even before a PSA tone pair has been confirmed by AMBA4.
2. Detection of Speech for Speaker Mute Control
On detection of speech because someone has pressed the SPEAK key and is speaking above the mute
level or squelch levels the speakers are turned on and will remain on for 3 seconds after speech has
stopped. This is to give the speakers some hysteresis so talking does not pop in and out.
3. Detection of Low R-Line Voltage
If the R-line is weak and falls below 6 Volts then a warning message is displayed if in the Generic mode on
the LCD screen. If it remains low, the then unit will fall into a deep sleep to conserve power, all background
functions, and LCD display will stop. This mode should only be used to store units on the store shelves. If in
‘deep-sleep’ the unit can be, awaken up by holding down the ‘Menu’ key for three seconds. If the R-line is
removed, the warning message ‘ZERO’ will be displayed beneath R-line Bar graph.
4. Pressing of SPEAK key
On pressing of the SPEAK key (a press to talk, ‘PTT’ action) the unit will wake up momentary if asleep and
display ‘SPEAK’ in the message text box on the Generic mode of the LCD screen. The ABMA4 will turn off
speakers and turn on the microphone. The unit will return to sleep mode as soon as Speak key is release.
5. Switching between Sleep and Deep Sleep modes
To save battery power when not in use, the ABMA4 goes to sleep when no keys are pressed after 30
seconds. The unit is woken when a PSA occurs (for only 8seconds), SPEAK (for only 1 second) or any of the
menu keys are pressed (30 seconds). The unit is not woken for ‘Call Exchange’ or ‘Call Local’ keys. These
just signal directly to the PSA controller. Sleep consists of turning off the LCD display and backlight. The unit
is still very active doing all other background tasks listed above.
The other mode is ‘Deep Sleep’. This should not occur in the field (see ‘Detection of Low R-Line Voltage’
in previous section above). Deep sleep mode is to save battery shelf life. In an emergency or on the test
bench to confirm operations, you can wake the ABMA4 from deep sleep either by pressing the ‘Menu’ key for
three seconds, adding power to the R-line or pressing ‘SPEAK’ key.
The activation from ‘Deep Sleep’ mode when the ‘SPEAK’ key is pressed (without PSA R-line power) is for
an emergency when you need to speak to other ABMA4 intercoms to attract attention. If the other ABMA4
intercoms have R-line power then the system will work as normal until the unit that has no R-line battery runs
flat. If all other ABMA4 units are in ‘Deep Sleep’ as well, they will only monitor for speech every few seconds,
upon the detection of which they will awake and turn speakers on. Thus in ‘Deep Sleep’ mode you need to
speak for longer than one second before the ABMA4 will open their speakers. This assumes there is enough
battery power in the units, which would be true for the case for a power-outage of a few days or weeks.

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6. Watchdog kicks
‘Watchdog’ is a background task that continuously monitors for tasks that have locked up (i.e. stopped). If
the task stops for more than 10 seconds, then it is kicked and the unit resets.
4. GENERIC DISPLAY DECRIPTION
When the unit powers up after going through the Austdac logo and version information, the Generic (default)
graphical mode is displayed on the LCD as seen below:
Figure 2: LCD Generic View
The LCD display is separated into three sections using bars. The top left shows battery health and speaker
volume state. Right of the bar shows external health of interface to PSA controller. The left bottom shows a
message box area for display messages such as ‘SPEAK’ when the SPEAK key is pressed.
Battery and Speaker Health Icons
Ic
on explanation
:
Icon
:
Full battery and not charging
Partly full battery and charging
Dead battery and charging
Dead battery, charging fault
Good Speakers (low volume)
Good Speakers (med volume)
Good Speaker (high volume)
Bad Speakers (speakers not
connected)
Table 1: Top Left Generic Icons
The current icon has bars that fluctuate from one bar to five bars depending on how much charge current is
flowing.
The hardware can show left or right speaker faults or both, as shown above. While in Generic Display view,
you can change the speaker output volume by pressing the up or down keys.

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PSA Health Interface Icons
Icon explanation
:
Icon
:
R-Line bar-graph
Voltage level of R-line at ±0.5V
resolution
Un-tested PSA loop
See “Comms Line” Menu to see
last confirm state.
Partly working PSA loop
Faulty PSA loop
Fully working PSA loop
Table 2: Top Right Generic Icons
The ‘PSA Loop’ icon flashes when a PSA test is occurring and shows that a change in state may happen.
The flashing will occur a few second after PSA to ensure the user notices any changes especially if it is a
short PSA.
A partly working PSA loop can happen if there is an S-line connection fault or V-line connection fault. If both
lines have a fault, then the unit cannot see the PSA controller and will display an un-tested PSA icon.
See System Test section below.
Text Box
The text box area of the screen provides the user with text information referring to the operation of AMBA4.
For example, it displays ‘SPEAK’ when the speak key is pressed or ‘LOW LINE VOLTAGE’ when the R-line
voltage is low.
5. CONFIGURATION MENU DESCRIPTION
While in Generic Display mode (see Figure 2), pressing the ‘Menu’ key will get the following menu options:
Figure 3: Menu Options
Each Configuration menu option provides either more detailed status information or the ability to change
settings in the ABMA4. To ‘Exit’ the menu display mode, press ‘Menu’. The ‘Menu’ key toggles you in and
out of the Configuration and Generic display modes. To enter a menu option (eg. ‘Battery’) you press the
‘Enter’ key. To move between menu options press the up (⇑) or down (⇓) keys.

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Battery Menu
This menu shows the health of battery status.
Figure 4: Battery Menu View
The figure 4 above, shows battery voltage in volts and charge current in mA units. The battery voltage
should be around 4.6 to 5.6Volts and the current between 0mA and 25mA maximum, depending on the
charge state of the battery.
To exit this menu, press either ‘Menu’ or ‘Enter’ key.
Comms Line
This menu shows the health of the interface to the PSA controller.
Figure 5: Comms Line View
Figure 5 gives a reading of the R-line voltage and PSA loop status. As in Generic mode, the PSA loop shows
the health of the V and S lines to the PSA controller in this menu. In addition, in this menu you have time and
confirmation of the last PSA. If ‘Cnfrm:’ has ‘Y’ next to, then directly above it will have the time in hh:mm:ss
since the last PSA was confirmed. If ‘Cnfrm: has ‘N’ next to it then PSA has not been confirmed and no time
will be displayed. The maximum number of hours recorded since last PSA confirm is 99hrs, which is 4 Days
and 3 hours.
To exit this menu press either ‘Menu’ or ‘Enter’ key.
Setting
This menu shows the current setting or configuration setting that can be made in the ABMA4:
Figure 6: Setting menu

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To enter a menu option (eg. ‘Volume’) you press the ‘Enter’ key. To move between menu options press the
up (⇑) or down (⇓) keys.
1. Volume Option
Allows you to adjust speaker volume levels using the up (⇑) or down (⇓) keys. The default
setting is ‘LOW’ and there are two settings above this i.e. ‘MED’ and ‘HIGH’ (see below).
2. Test Speakers
Test the speakers by creating a tone and measuring current usage. If no current is detected
then no speakers are connected (see below).
3. Mute Level
Allows you to go into the Mute sub menu (see below).
4. Menu to Exit
Either by pressing ‘Menu’ or moving to this selection and pressing ‘Enter’ will return you to the
previous main menu.
You can exit at any time by pressing the ‘Menu’ key.
1. Volume Option
Figure 7: Volume Menu View
The Volume of the speaker output can be adjusted using the up (⇑) or down (⇓) keys. You have three levels:
‘LOW’, ‘MED’ and ‘HIGH’. The volume icon changes depending on different volume levels. The settings can
be used to set the speaker volume level depending on your current position along the system cable
You can exit at any time by pressing the ‘Menu’ or ‘Enter’ key.
2. Test Speakers
This Configuration Menu function allows testing of Speakers and Output Amplifiers. This is a critical part of
the operation of the ABMA4. Without working speakers, the PSA alerts will not be heard and the unit fail as
working intercom. As soon as you enter this menu, the speakers are tested by generating a 1.2KHz tone into
both stereo speakers. The Test Speakers menu view look like:
Figure 8: Test Speaker Menu View
After the test depending on the state of the speakers, (i.e. working or not) the Speaker Icons will be
displayed as crossed out if not working or as low volume speaker icons. For example, as figure below shows

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that left hand speaker is good and right hand speaker is faulty. Either the fault is due to an open circuit to the
speaker or speaker is not pulling enough current for normal operations.
The tone occurs for almost a second for menu changing from ‘Testing’ to ‘Complete’.
Figure 9: Test Speakers Completed View
After the test has been completed, you can exit at any time by pressing either the ‘Menu’ or Enter Key.
3. Mute Level Menu
This menu allows you to view the mute level state and to adjust the mute level. Mute level is sometimes
called Squelch (2-way radio terminology) and is used to turn the speakers off to save battery power until
someone talks or PSA is received. You should adjust the mute level for noisy environments such as
background electrical noise or RF pickup, which will cause speakers to open (turn-on). The default level is
set to ‘Low’ noise. There is a setting below that called ‘Clean’ for very electrically quiet areas and two setting
above that called ‘Med’ and ‘High’ for noisier areas. The menu is shown:
Figure 10: Mute Level Menu
To enter a menu option (eg. ‘View Mute’) you press the ‘Enter’ key. To move between menu options press
the up (⇑) or down (⇓) keys.
1. View Mute
Allows you to view the mute level.
2. Set Mute
To enter ‘SET MUTE’ you must enter a four-digit password. The password prevents unauthorised access
to the AMBA4 and should be setup when an authorised technician installs the unit. The current password
for version 1.0 of the software is 4321 and is set using the up (⇑) or down (⇓) keys and the ‘Enter’ key.
Below is shown the ‘Password Access’ screen and follow-on screen once a successful password has been
entered:

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Figure 11: Password Access screen
Figure 12: Set Mute Level Low
Figure 13: Set Mute Level Medium
4. About Menu
The ‘About’ menu show Austdac Logo and information on the product model and software version. To exit,
either press ‘Menu’ or ‘Enter keys.
The following screen will be displayed:
Figure 14: About Menu logo
After a further two second the following information will be displayed:

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Figure 15: About Menu Information
6. INSTALLATION AND CONNECTIONS
Cable Shielding
From “PRE-START ALARM AND COMMUNICATIONS SYSTEM TYPE PSACS1” user manual (20-079-12)
the following system cables are used: G2000 and G2000B both have a foil and drain wire and cable CABL25
has no shielding at all. The cable is a very important part in the system as it carries all the signals and
distributes power to all the system components. Of the conductors, two are larger in cross sectional area
than the other two. The two larger cross sectional area conductors are used to distribute power to the system
components while the smaller conductors are used to convey signals between the various system
components. The smaller conductors are the ones that have a foil sheath in the G2000 and G2000B cables.
The connection of foil sheath and drain wire is critical for correct installation. You must either use the shield
cable correctly with the ABMA4 R-Line (Common line) terminated with a shield drain wire at each ABMA4 or
not use a shield foil/drain wire at all, which is the Austdac default method. The shield is not passed through
and is left floating as depicted in the electrically simplified figure 16 below:
Figure 16: Simplified Un-Shielded Circuit
If the shield is passed through from one cable to another between ABMA4 terminations and is not terminated
at the R-Line then this is electrically noisier than having no shield at all. The coupling between shield and the
V and S cores has the effect of giving alternative PSA signal paths that can cause the PSA Controller and
ABMA4s to receive false confirmations on tail end units.

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7. SYSTEM TEST AND FAULT FINDING
The ABMA4 has a graphical display that can aid in fault finding along with the PSA Controller and End Unit.
The primary system test and fault analysis occurs when the PSA Controller gets a confirmation from the end
unit. The TEU (tail end unit) returns a signal via the S-Line and the user can hear a ‘hee’-‘haw’. If the user
only hears a ‘hee’ or single tone pair then PSA Controller has not got a confirmation. The ABMA4 helps by
displaying the system cable status by showing the R-Line, V-Line and S-Line states.
In Generic Display mode (see Generic Display Description section) you can view the R-Line voltage bar-
graph and the PSA Loop status at a glance. Alternatively you can go into ‘Menu Setting’ to the ‘Comms Line’
menu and get more information on R-Line digital reading and the time the ‘Last PSA occurred. Below is a
flow diagram of a System Test.
Flow Diagram Description
Following the right hand side of the diagram, you need to have a PSA confirmation from the controller and
each of the ABMA4’s has a PSA Loop to confirm status to get a System Test Passed. You should check that
the ‘Last PSA Confirm’ time is correct by going into ‘Comms Line’ menu (see Configuration Menu Description
and Fault Analysis below). If you get a PSA confirm from the controller but a ABMA4 unit doesn’t show PSA
Loop confirmation then fault is not in the system cable but between this cable and the unit itself (i.e. V and S
lines crossed or cut etc..).
If you do not get a PSA confirmation from the controller, then you need to read the section on Fault Analysis.
Fault Analysis
Fault Analysis of the system looks at the PSA Loop graphic of the ABMA4 to work out where on the line is a
fault. Possible reasons that a PSA controller does not receive a confirmation are as follows:
1. End Unit is not connected or has not enough volts (cable too long or two many units or system has
be used heavily and now all units are drawing maximum current).
2. There is break in the V-line between the PSA Controller and TEU
3. There is break in the S-line between the PSA Controller and TEU
4. There is break in the R-line or M-line between the PSA Controller and the TEU
SYSTEM TEST
Do we get a
PSA Confirm?
Does each
ABMA4 show
PSA Confirm?
Faulty System
See Fault Analysis
Termination fault
between ABMA4 and
system cable!
System Test
Passed

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5. There is a combination of the three above
Analysis 1: Tail End Unit Is Not Connected
Shown below is an example of how to interpret the graphical interface on a group of ABMA4’s when a TEU is
faulty.
Figure 17: TEU Fault Example
The example above has a cut down view of four ABMA4s and an enlarged PSA Loop Icon for easier
readability. The reasons for TEU not working are that it has been installed incorrectly, the cable too long or
that it is mixing with an old BMA intercom (i.e. such as LEGACY INTERCOMS DAC TYPE STAGE II which
don’t have any current limiting) so that if the system is heavily used the current usage goes up and line
voltage drops.
Analysis 2: There is a break in the V-line
The examples below show the enlarged PSA Loop Icon at varying states depending on where the V-line has
been broken/cut.
Figure 18: V-Line break at the front

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Figure 19: V-Line break in the middle
Figure 20: V-Line break at the end
The V-Line carries the PSA tones and a break it this line means that you will only get a ‘hee’ sound and the
PSA controller will not get a confirmation. This should be your primary method of determining if the system
OK or not.
The example above shows how the ABMA4 graphical display can help determine where the V-Line break
has occurred. Note this is the most difficult to detect and analyse as the signal may not reach the end
ABMA4 unit. The easiest analysis would involve just a walk down the system cable and a look at each
generic display (i.e. wakeup each unit with a menu key press) to work out where the V-Line tick (√) changes
to a cross (×). Then the break will occur between these units. Unfortunately, because of the nature of system
cable and installation history, how each ABMA4 interprets the V-Line signal after the cable break is
indeterminate. If a cable is a ‘clean’ electrical (i.e. good shielding and correctly wired) then units after the V-
Line break will not display any PSA Loop status. They will not have updated their display and the PSA Loop
will have blanks (see figures on the end ABMA4 in figures 18 and 19).

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If a system cable has electrical coupling between wires (no shielding and default installation) then the unit
after the V-Line break will update the PSA Loop Icon with two crosses (×) as shown in the figures above. The
crosses (×) indicate that there was a PSA signal detected but the level is weak enough to be assumed to be
decoupling noise. The last and most likely occurrence is a combination of both, where some units have two
crosses (×) and some units have blanks (or no valid confirmation).
You may have a break in the S-Line as well but until the TEU can return the signal (i.e. V-Line is OK) you
have no way of analysing this scenario. A possible pit-fall in analysis of the ABMA4 graphical display is that
you have a system working and then a fault occurs. The problem arises because the display will only show a
PSA loop status from the last received PSA and if the V-Line is cut then the ABMA4s that do not have any V-
Line signal do not update. So they will display two ticks (√)! You must remember (see fault flow diagram)
that a fault occurred because you did not get a confirmation from the PSA Controller. You can also check the
‘Comms Line’ menu (see Configuration Menu section above) to see when the last confirm occurred. The
ABMA4 unit that has two ticks will have an old confirm time displayed. An alternative method to overcome
the problem of the generic screen displaying two ticks is to reset all the ABMA4 along the system cable by
turning off the PSA Controller for ten (10) minutes. This will reset all ABMA4s to show PSA Loop with blanks
or un-initialized state. Then when you do the analysis you will only get cross (×) or blanks in the PSA loop
icon.
Analysis 3: There is break in S-line
The examples below show an enlarged PSA Loop Icon at varying states depending on where the S-line has
been broken/cut.
Figure 21: S-Line break at the front

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Figure 22: S-Line break in the middle
Figure 23: S-Line break at the end
The S-Line carries the return PSA tones back from the TEU. A break in this line means you should get only a
‘hee’ after the break and the PSA controller will not get a confirmation. Repeating, this should be your
primary method of determining if the system OK or not.
The example above shows how the ABMA4 graphical display can help determine where the S-Line break
has occurred. This method is easier to analyse than the V-Line break because all ABMA4 units will have
updated screens. The method of detection is just a matter of walking between the TEU and PSA Controller
and determining where a tick (√) changes to a cross (×) on the S-Line. As shown in the figures above, a
break occurs between a unit with a tick (√) and unit with a cross (×). Note the ABMA4 will be in sleep mode
and will need waking up by pressing the ‘menu’ key to show the display.

I.S. INTERCOM 20-278-12
TYPE ABMA4 USER MANUAL 20 OF 21 Issue: 05
Analysis 4: There is a break in the R-line or M-line
Again as in the analysis above, if there is a break in the R-line (common line) the return PSA tones back
from the TEU will not happen. You will only get a ‘hee’ sound after the break and the PSA controller will not
get a confirmation. Again, this should be your primary method of determining if the system OK or not.
The examples below show an enlarged R-Line bar-graph Icon at varying states depending on where the R-
line has been broken/cut.
Figure 24: R-Line break at the front
Figure 25: R-Line break in middle