Sonifex CM-TB8 Instruction Manual

CM-TB8 8 Channel Talkback
Control Unit
User Handbook

CM-TB8 8 Channel Talkback Control Unit User Handbook
CM-TB8 8 CHANNEL TALKBACK CONTROL UNIT
CM-TB8 8 CHANNEL TALKBACK CONTROL UNIT HANDBOOK
This handbook is for use with the following product:
CM-TB8 8 Channel Talkback Control Unit
©Sonifex Ltd, 2013
All Rights Reserved
Revision 1.01, June 2013
Sonifex Ltd, 61, Station Road, Irthlingborough,
Northants, NN9 5QE, England.
Tel: [phone]
Fax: [phone]
Email: [email protected].uk
Website: http://www.sonifex.co.uk
Information in this document is subject to change without notice and does not represent a commitment on the part of
the vendor. Sonifex Ltd shall not be liable for any loss or damage whatsoever arising from the use of information or any
error contained in this manual.
No part of this manual may be reproduced or transmitted in any form or by any means, electronic or mechanical,
including photocopying, recording, information storage and retrieval systems, for any purpose other than the purchaser’s
personal use, without the express written permission of Sonifex Ltd. Unless otherwise noted, all names of companies,
products and persons contained herein are part of a completely fictitious adaptation and are designed solely to
document the use of Sonifex product.

CM-TB8 8 Channel Talkback Control Unit User Handbook c
CONTENTS
CONTENTS
Warranty i
Warranty and Liability i
Unpacking the CM-TB8 iii
Returning the Warranty Card iii
Safety Information iv
Safety of Mains Operated Equipment iv
Voltage Setting Checks iv
Fuse Rating iv
Power Cable and Connection iv
Ordering the Correct Mains Lead v
Installation Information v
Atmosphere v
Electromagnetic Radiation v
WEEE & RoHS Directives - Sonifex Statement vi
Introduction 1
Front Panel Controls, Connections & Indicators 2
Headphone Output Connection 2
Microphone Input Connection 2
Headset Connection 2
Talk Level Indicators 2
Input Select Indicators 2
Multi-Function Rotary Control 2
Group Talk Button 3
Channel 1 to 8 Talk Buttons 4
Channel 1 to 8 IFB/4W Select Switches 4
Channel 1 to 8 Monitor Level Potentiometers 4
Loudspeaker Mute Button 5
Loudspeaker Dim Potentiometer 5
Monitor Level Potentiometer 5
Rear Panel Connections 6
4W IN Input Connections 6
TB OUT Output Connections 6
IFB A & B Programme Input Connections 6
MIC Output Connection 6
Remote Connections 6
Ethernet Connection 6
LS Output Connection 6
Line-Up Tone Mode 7
Remotes 8
Remotes 1 – Outputs 8
Remotes 2 – Inputs 8
Configuration Options 10
On-Board Conguration Mode 10
Embedded Web Server 11
Home Page 13
Network Settings Page 13
Display Settings Page 14
Talk Level Settings Page 15
Group Talk Settings Page 16
Load Settings Page 17
Save Settings Page 18
Update Page 18

dCM-TB8 8 Channel Talkback Control Unit User Handbook
CONTENTS & FIGURES
CONTENTS & FIGURES
Configuration Option Defaults 20
Configuration Template Set 1 (read only) 20
Configuration Template Set 2 (read only) 20
Configuration Template Sets 3 to 6 21
Connection Example 22
Button Operation Reference 23
Connection Details 24
Headphone Output – ¼ inch (6.35mm) stereo jack socket 24
Microphone Input – Electronically balanced 3 pin female XLR-3 24
Headset – 5 pin female XLR-5 (microphone input is electronically balanced) 24
4-Wire Inputs – Transformer balanced 3 pin female XLR-3 24
Talkback Outputs – Transformer balanced 3 pin male XLR-3 24
IFB Inputs – Transformer balanced 3 pin female XLR-3 24
Microphone Output – Electronically balanced 3 pin male XLR-3 24
Remotes 1 – 15-way ‘D’-type socket 24
Remotes 2 – 15-way ‘D’-type socket 25
Loudspeaker Output – ¼ inch (6.35mm) jack socket 25
Technical Specification 26
CM-TB8T Introduction 28
Enabling the Telephone Interface 28
Making a Telephone Call 29
Direct Dialling 29
Dialling Using an External Telephone Handset 29
Receiving a Telephone Call 29
Handling a Connected Telephone Call 30
Ending a Telephone Call 30
Embedded Web Server 31
PSTN Settings Page 31
PSTN Telephone Interface Connection Details 32
Telephone Line – RJ11 Socket 32
Telephone Handset – RJ11 Socket 32
Figures
Fig A: Packing List iii
Fig B: Power Connections iv
Fig C: Mains Lead Table v
Fig 1-1: System Block Diagram. 1
Fig 2-1: CM-TB8 Front Panel. 2
Fig 3-1: CM-TB8 Rear Panel. 6
Fig 6-1: Home Page. 13
Fig 6-2: Network Settings Page. 13
Fig 6-3: Display Settings Page. 14
Fig 6-4: Microphone Settings Page. 14
Fig 6-5: Talk Level Settings Page. 15
Fig 6-6: Group Talk Settings Page. 16
Fig 6-7: Channel Settings Page. 16
Fig 6-8: Load Settings Page. 17
Fig 6-9: Save Settings Page. 18
Fig 6-10: Update Page. 18
Fig 8-1: Connection Example. 22
Fig 12-1: Channel Settings Page 28
Fig 12-2: PSTN Settings Page 31

CM-TB8 8 Channel Talkback Control Unit User Handbook i
Warranty
Warranty and Liability
Important: the purchaser is advised to read this clause
(a) The Company agrees to repair or (at its discretion) replace Goods which are found to
be defective (fair wear and tear excepted) and which are returned to the Company
within 12 months of the date of despatch provided that each of the following
are satisfied:
(i) notification of any defect is given to the Company immediately upon its
becoming apparent to the Purchaser;
(ii) the Goods have only been operated under normal operating conditions and
have only been subject to normal use (and in particular the Goods must have
been correctly connected and must not have been subject to high voltage or
to ionising radiation and must not have been used contrary to the Company’s
technical recommendations);
(iii) the Goods are returned to the Company’s premises at the Purchaser’s expense;
(iv) any Goods or parts of Goods replaced shall become the property of
the Company;
(v) no work whatsoever (other than normal and proper maintenance) has been
carried out to the Goods or any part of the Goods without the Company’s prior
written consent;
(vi) the defect has not arisen from a design made, furnished or specified by
the Purchaser;
(vii) the Goods have been assembled or incorporated into other goods only in
accordance with any instructions issued by the Company;
(viii) the defect has not arisen from a design modified by the Purchaser;
(ix) the defect has not arisen from an item manufactured by a person other than
the Company.
In respect of any item manufactured by a person other than the Company, the Purchaser
shall only be entitled to the benefit of any warranty or guarantee provided by such
manufacturer to the Company.
(b) In respect of computer software supplied by the Company the Company does not
warrant that the use of the software will be uninterrupted or error free.
(c) The Company accepts liability:
(i) for death or personal injury to the extent that it results from the negligence of
the Company, its employees (whilst in the course of their employment) or its
agents (in the course of the agency);
WARRANTY
WARRANTY

ii CM-TB8 8 Channel Talkback Control Unit User Handbook
(ii) for any breach by the Company of any statutory undertaking as to title, quiet
possession and freedom from encumbrance.
(d) Subject to conditions (a) and (c) from the time of despatch of the Goods from the
Company’s premises the Purchaser shall be responsible for any defect in the Goods
or loss, damage, nuisance or interference whatsoever consequential economic or
otherwise or wastage of material resulting from or caused by or to the Goods. In
particular the Company shall not be liable for any loss of profits or other economic
losses. The Company accordingly excludes all liability for the same.
(e) At the request and expense of the Purchaser the Company will test the Goods to
ascertain performance levels and provide a report of the results of that test. The
report will be accurate at the time of the test, to the best of the belief and knowledge
of the Company, and the Company accepts no liability in respect of its accuracy
beyond that set out in Condition (a).
(f) Subject to Condition (e) no representation, condition, warranty or other term,
express or implied (by statute or otherwise) is given by the Company that the Goods
are of any particular quality or standard or will enable the Purchaser to attain any
particular performance or result, or will be suitable for any particular purpose or use
under specific conditions or will provide any particular capacity, notwithstanding
that the requirement for such performance, result or capacity or that such particular
purpose or conditions may have been known (or ought to have been known) to the
Company, its employees or agents.
(g) (i) To the extent that the Company is held legally liable to the Purchaser for any
single breach of contract, tort, representation or other act or default, the
Company’s liability for the same shall not exceed the Price of the Goods.
(ii) The restriction of liability in Condition (g)(i) shall not apply to any liability
accepted by the Seller in Condition (c).
(h) Where the Goods are sold under a consumer transaction (as defined by the
Consumer Transactions (Restrictions on Statements) Order 1976) the statutory
rights of the Purchaser are not affected by these Conditions of Sale.
WARRANTY
WARRANTY

CM-TB8 8 Channel Talkback Control Unit User Handbook iii
Unpacking the CM-TB8
The CM-TB8 is shipped with the following equipment. Please check your packaging to
ensure that you have all of the items below. If anything is missing, please contact the
supplier of your equipment immediately.
Item Quantity CM-TB8
CM-TB8 1
IEC mains lead fitted with moulded mains plug 1
Handbook and warranty card 1
Fig A: Packing List
Each CM-TB8 is shipped in protective packaging and should be inspected for damage
before use. Where an item is found to have transit damage, notify the carrier immediately
with all the relevant details of the shipment. Packing materials should be kept for
inspection and also for if the product needs to be returned.
Returning the Warranty Card
In order to register the date of purchase so that we can keep you informed of any design
improvements or modifications, it is important to complete the warranty registration
document that is enclosed and return it to Sonifex Ltd in the UK, or register online at
www.sonifex.co.uk/register
For your own records you should write down the serial number (which can be found on the
rear of the CM-TB8).
Serial Number ………………………………………
WARRANTY
WARRANTY

iv CM-TB8 8 Channel Talkback Control Unit User Handbook
Safety Information
Safety of Mains Operated Equipment
This equipment has been designed to meet the safety regulations currently
advised in the country of purchase and it conforms to the safety regulations
specified by use of the CE Mark.
Warning : There are no user serviceable parts inside the equipment. If you should ever
need to look inside the unit, always disconnect the mains supply before removing the
equipment covers.
Voltage Setting Checks
Ensure that the machine operating voltage is correct for your mains power supply by
checking the box in which your CM-TB8 was supplied. The voltage is shown on the box
label. Please note that all CM-TB8s have a universal power supply.
Fuse Rating
The CM-TB8 is supplied with a single fuse in the live conducting path of the mains power
input. For reasons of safety it is important that the correct rating and type of fuse is
used. Incorrectly rated fuses could present a possible fire hazard, under equipment fault
conditions. The fuse rating for the CM-TB8 is:
Universal 85-264V operation - 2A 5x20mm SB
The active fuse is fitted on the outside rear panel of the unit.
Power Cable and Connection
An IEC power connector is supplied with the CM-TB8 which has a moulded plug attached
– this is a legal requirement. If no moulded plug has been supplied with your CM-TB8,
please contact your supplier, because an IEC connector is always supplied from the Sonifex
factory.
If for any reason, you need to use the CM-TB8 with a different power cable, you should use
the following wiring guidelines.
Wire Colour Connection
Green, or green and yellow Earth (E)
Blue, or black Neutral (N)
Brown, or red Live (L)
Fig B: Power Connections
SAFETY INFORMATION
SAFETY INFORMATION

CM-TB8 8 Channel Talkback Control Unit User Handbook v
Connect the equipment in accordance with the connection details and before applying
power to the unit, check that the machine has the correct operating voltage for your mains
power supply.
Important Note : The terminal marked on the rear panel must be earthed.
Ordering the Correct Mains Lead
When ordering a CM-TB8 from Sonifex, it is helpful if you can specify your required
operating voltage and mains lead. After the product code add:
UK, for 230V, UK 3 pin to IEC lead
EC, for 230V, European Schuko 2 pin to IEC lead
US, for 115V, 3 pin to IEC lead
AU for 230V, Australasian 3 pin to IEC lead
Fig C: Mains Lead Table
E.g. order CM-TB8 UK for a UK IEC lead to be supplied.
Installation Information
Atmosphere
The units should be installed in an area that is not subject to excessive temperature
variation (<0°C, >50°C), moisture, dust or vibration.
Electromagnetic Radiation
The cover is connected to earth by means of the fixing screws. It is essential to maintain
this earth ground connection to ensure a safe operating environment and provide
electromagnetic shielding.
SAFETY INFORMATION
SAFETY INFORMATION

vi CM-TB8 8 Channel Talkback Control Unit User Handbook
WEEE & RoHS Directives - Sonifex Statement
The Waste Electrical and Electronic Equipment (WEEE) Directive was agreed on
13 February 2003, along with the related Directive 2002/95/EC on Restrictions
of the use of certain Hazardous Substances in electrical and electronic
equipment (RoHS).
The Waste Electrical and Electronic Equipment Directive (WEEE) aims to minimise the
impacts of electrical and electronic equipment on the environment during their life times
and when they become waste. It applies to a huge spectrum of products. It encourages
and sets criteria for the collection, treatment, recycling and recovery of waste electrical and
electronic equipment. All products manufactured by Sonifex Ltd have the WEEE directive
label placed on the case. It gives a contact for individuals who are unsure about the correct
procedure when the product has reached its “end of use”.
Sonifex Ltd will be happy to give you information about local organisations that can
reprocess the products, or alternatively all products that have reached “end of use”can be
returned to Sonifex and will be reprocessed correctly free of charge.
Sonifex Ltd has phased out the use of certain hazardous substances identified in the
European Union’s Restriction of Hazardous Substances (RoHS) directive. The RoHS
directive limits the use of certain hazardous substances currently used in EEE manufacture,
including lead, mercury, cadmium, hexavalent chromium, and halide-containing
compounds PBB (polybrominated biphenyl) and PBDE (polybrominated diphenyl ether).
Elimination of these substances will result in more environmentally friendly recycling
of electronic equipment. For the products which Sonifex manufacture, the main area
where products were affected was in the use of lead for manufacturing and assembling
electronics circuit boards.
Sonifex Ltd practices lead-free (LF) manufacturing processes. LF solder is used on the
surface-mount PCB manufacturing processes and for hand soldering. The printed circuit
boards (PCBs) used are either gold plated, or immersion tin plated, both of which use no
lead. Historically the PCBs were hot air solder levelled (HASL) PCBs which used tin/lead
based solder.
The manufacturing processes include the assembly of purchased components from
various sources. Product is offered as RoHS compliant, or LF, only after sufficient evidence
is received from the component manufacturers that their components are RoHS compliant.
Sonifex Ltd relies solely on the distributor, or manufacturer, of the components for
identification of RoHS compliance. Thus whilst every effort is made to ensure compliance,
Sonifex Ltd makes no warranty, or certification, or declaration of compliance concerning
said components.
Sonifex Ltd defines “Lead Free”as pertaining to any product, which has been manufactured
by Sonifex Ltd using components which have been declared by the manufacturers as
“Lead Free”. All statements by Sonifex Ltd of RoHS compliance are based on component
manufacturer documentation.
WEEE & ROHS DIRECTIVE
WEEE & ROHS DIRECTIVE

CM-TB8 8 Channel Talkback Control Unit User Handbook 1
INTRODUCTION
1
INTRODUCTION
Introduction
The CM-TB8 Talkback Control Unit is a powerful and highly flexible self contained
communications unit allowing multiple 4-wire and IFB connections within a single 1U
rack space. Using the latest DSP technology, the CM-TB8 integrates a high quality, digitally
controlled audio system with an intuitive and configurable user interface. It offers easy
connection to any industry standard talkback system including the Sonifex CM-TBU line
listen unit plus the CM-CU1 and CM-CU21 commentator units.
The CM-TB8 provides 8 channels of 4-wire communication, with 2 additional IFB inputs that
can be routed to each channel. The unit has individual connections for a microphone and
headset, and the gain for each input can be independently set. Phantom power and a wide
gain range ensure support for most microphone types. All of the audio processing is done
in the digital domain. This gives greater control of the audio mixing and routing functions
and allows smoother changes in signal level. Likewise, the volume potentiometers on the
front panel control gain digitally, ensuring noise free operation.
Fig 1-1: System Block Diagram

2CM-TB8 8 Channel Talkback Control Unit User Handbook
FRONT PANEL CONTROLS,
CONNECTIONS & INDICATORS
FRONT PANEL CONTROLS, CONNECTIONS & INDICATORS
2
Front Panel Controls, Connections & Indicators
Fig 2-1: CM-TB8 Front Panel
Headphone Output Connection
The headphone output is via a ¼ inch (6.35mm) stereo jack socket capable of driving 32Ω -
600Ω professional headphones. Lower impedance headphones should not be used.
Microphone Input Connection
The electronically balanced microphone input is via a 3 pin female XLR-3 connector. The
available gain for this input ranges from +6dB to +69dB. Phantom powered microphones
are supported on this input.
Headset Connection
The headset connection is via a 5 pin female XLR-5 connector. It shares the same input
and output circuits as the separate microphone and headphone, but the gain settings
are independent and the available range is from +6dB to +69dB. Changing the input type
automatically selects the corresponding gain settings. Phantom power is also available on
this input.
The microphone and headset inputs are protected by a level limiter. The limiter will start to
function when the input signal exceeds approximately +8.5dB. When the limiter is active,
the input select LED indicators will illuminate red instead of amber. When the input signal
is reduced and the limiter turns off, the input select indicators return to amber illumination.
Talk Level Indicators
In the normal operating mode, the left indicator illuminates green when the gain adjusted
microphone signal exceeds 0dB, and the right indicator illuminates red when the signal
exceeds +8dB.
Input Select Indicators
In the normal operating mode, these indicators illuminate amber to show which
microphone type is currently selected, and whether phantom power is enabled. They also
show when the microphone limiter is actively limiting the level of the signal, by changing
from amber to red.
Multi-Function Rotary Control
The rotary control has various functions which are dependent on the current operating
mode.
Headphone
Socket
Microphone
Input
Connection
Headset
Connection
Talk Level
Indicators
Input Select
Indicators
Multi-Function
Rotary Control
Channel
IFB/4W
Select Switch
Loudspeaker
DIM
Potentiometer
Loudspeaker
Mute Button
Channel
Monitor Level
Potentiometer
Channel
Talk
Button
Monitor
Level
Potentiometer
Loudspeaker

CM-TB8 8 Channel Talkback Control Unit User Handbook 3
FRONT PANEL CONTROLS, CONNECTIONS & INDICATORS
2
FRONT PANEL CONTROLS,
CONNECTIONS & INDICATORS
In the normal operating mode, the rotary control can adjust the talk level. This is the level
of the microphone signal routed to the talkback outputs. The selected microphone gain
settings and the subsequent microphone output level at the rear panel connector are not
changed.
To adjust the talk level: first ensure that the function is enabled and the required range
of adjustment has been selected. See the Talk Level Settings Page in the Embedded Web
Server section on page 11. Turn the rotary control to increase or decrease the current
talk level within the limits set by the talk level adjust options. There is an additional option
that requires the rotary control to be pressed before any adjustment to the talk level can
be made. With this option selected, the adjustment mode will timeout after 1 second of
inactivity of the rotary control.
The rotary control also accesses the microphone select and microphone gain and filter
setup modes.
To access the microphone select and microphone gain and filter setup modes: press and
hold the rotary control for 3 seconds whilst in the normal operating mode. The two talk
level LEDs will illuminate red. Turn the rotary control to select the mode to enter, either
microphone gain and filter setup mode when the two talk level LEDs are illuminated, or
microphone select mode when MIC, Phantom and HS LEDs are illuminated. When the
required LEDs are illuminated, press the rotary control to enter the associated mode. If the
rotary control is not turned or pressed for 3 seconds, this function will timeout and the unit
will return to normal operation. Please note, entering microphone gain and filter setup
mode resets the current talk level adjust value to zero.
To change the selected microphone type: once in microphone select mode, the currently
selected microphone setting LEDs will flash. Turn the rotary control to change the
selection. Both microphone and headset type can be selected with or without phantom
power. A brief press on the rotary control will return the unit to normal operation.
To change the microphone gain and filter: once in the microphone gain and filter setup
mode, the talk buttons on channels 1-8 will illuminate to show the approximate current
gain setting for the currently selected microphone. Turn the rotary control to increase or
decrease the gain. With no buttons illuminated, the gain is approximately 6dB. The gain
increases by approximately 8dB as each talk button is illuminated with the maximum gain
of approximately 69dB gain when all talk buttons are illuminated. The talk level LEDs will
show the current level of the microphone signal as it exceeds 0dB and +8dB respectively,
and the microphone signal can be monitored in the headphones.
The state of the microphone filter is shown on the LS mute button LED. If the LED is
illuminated red, the filter is on. Press the LS mute button to enable or disable the filter.
Once the required microphone gain and filter setting has been set, a brief press on the
rotary control will return the unit to normal operation.
Group Talk Button
The group talk button simultaneously activates all of the talk buttons that have been

4CM-TB8 8 Channel Talkback Control Unit User Handbook
FRONT PANEL CONTROLS,
CONNECTIONS & INDICATORS
FRONT PANEL CONTROLS, CONNECTIONS & INDICATORS
2
included in the group talk function. By default, all channels are included. When the group
talk function is active, the button illuminates red, as do the talk buttons on the channels
activated by the group talk function. By default, the button has a momentary action that
will automatically latch in the on state if pressed briefly.
Channel 1 to 8 Talk Buttons
Each talk button routes the currently selected microphone signal to the corresponding
talkback output. When a talk button is active, it illuminates red. The channels audio call
indication illuminates the talk button green when the signal level on the corresponding
4W IN input rises above -12dB. The audio call is not shown on talk channels that are active.
By default, the talk buttons have a momentary action that will automatically latch in the on
state if pressed briefly.
Channel 1 to 8 IFB/4W Select Switches
These switches select the operating mode for each channel, either 4 wire or interruptible
fold back. The IFB input to each channel can be either the channels own 4W IN input, or
one of the two dedicated programme inputs, IFB A or IFB B. This selection is made in the
configuration options using either the on-board configuration mode or the embedded
web server. See the Configuration Options section on page 10. As an alternative to
the standard IFB modes, where the microphone signal interrupts the IFB signal when the
channel is active, an additional option allows the microphone signal to be mixed with
the IFB signal. In this mode, when a talk channel is activated, the level of the selected IFB
input signal on that channel is reduced by 12dB prior to being mixed with the microphone
signal.
To use a talk channel in 4W mode: put the IFB/4W switch in the 4W position. In this
mode, the signal on the 4W IN input connector is routed to the headphones/headset and
loudspeaker at the level set by the channels own monitor level potentiometer, with the
overall level controlled by the MON level potentiometer. When the talk button is pressed,
the microphone signal is routed to the channels talkback output at the TB OUT connector,
and the level of the feed to the loudspeaker (not headphones/headset) is reduced by the
level preset by the dim potentiometer.
To use a talk channel in IFB mode: put the IFB/4W switch in the IFB position. In this
mode, the signal on the 4W IN input connector is routed to the headphones/headset and
loudspeaker at the level set by the channels own monitor level potentiometer, with the
overall level controlled by the MON level potentiometer. The signal from the selected IFB
input, either the channels own 4W IN input or one of the dedicated programme inputs,
IFB A or IFB B, is routed to the talkback output at the TB OUT connector. When the talk
button is pressed, the signal at the talkback output is either replaced by or mixed with the
microphone signal, and the level of the feed to the loudspeaker (not headphones/headset)
is reduced by the level preset by the dim potentiometer.
Channel 1 to 8 Monitor Level Potentiometers
These controls set the level of the signal that is routed to the monitor headphones/headset
and loudspeaker from each channels input.

CM-TB8 8 Channel Talkback Control Unit User Handbook 5
FRONT PANEL CONTROLS, CONNECTIONS & INDICATORS
2
FRONT PANEL CONTROLS,
CONNECTIONS & INDICATORS
Loudspeaker Mute Button
The loudspeaker mute cuts the signal fed to the loudspeaker and the loudspeaker output
on the rear panel. The mute can also be activated via a remote input, see the Remote
section on page 8. The button has a latching action and illuminates red when activated
or flashes red to indicate the loudspeaker mute has been activated by the remote input.
The button also indicates when the loudspeaker dim is active by illuminating green. The
mute button does not affect the signal routed to the headphones.
Loudspeaker Dim Potentiometer
The loudspeaker dim pre-set potentiometer controls the level of attenuation applied to
the signal fed to the loudspeaker and rear panel loudspeaker output when any of the talk
channels are active, or the loudspeaker dim remote input is active. The attenuation range is
between full on and muted and it is adjusted using a small flat blade screwdriver.
Monitor Level Potentiometer
The monitor level potentiometer controls the overall level of the signal routed to the
headset/headphone outputs, the loudspeaker and the loudspeaker output on the rear
panel.

6CM-TB8 8 Channel Talkback Control Unit User Handbook
REAR PANEL CONNECTIONS
REAR PANEL CONNECTIONS
3
Rear Panel Connections
Fig 3-1: CM-TB8 Rear Panel
4W IN Input Connections
The transformer balanced 4W IN inputs are via 3 pin female XLR-3 connectors. These are
the main audio inputs to each channel.
TB OUT Output Connections
The transformer balanced TB OUT talkback outputs are via 3 pin male XLR-3 connectors.
These are the main audio outputs from each channel.
IFB A & B Programme Input Connections
The transformer balanced IFB inputs are via 3 pin female XLR-3 connectors.
MIC Output Connection
The electronically balanced microphone output is via a 3 pin male XLR-3 connector. It
outputs the gain adjusted, level limited signal from the selected microphone or headset
input.
Remote Connections
The remote connections are via two 15-way ‘D’-type sockets. All of the remote outputs are
on the remote 1 connector, whilst the inputs are all on the remote 2 connector. See the
Remotes section on page 8 for connection details.
Ethernet Connection
The Ethernet connection provides 100Mb network capabilities via a RJ45 connector.
LS Output Connection
The loudspeaker output is via a ¼ inch (6.35mm) jack socket. When an external
loudspeaker is connected, the internal loudspeaker is muted.
4W Inputs
Talkback Outputs
IFB Inputs
Microphone
Output
Mains Power
Inlet Ethernet
Remotes Loudspeaker
Output

CM-TB8 8 Channel Talkback Control Unit User Handbook 7
LINE-UP TONE MODE
4
LINE-UP TONE MODE
Line-Up Tone Mode
The CM-TB8 has a built in Test Tone generator which selectively routes a line-up tone of
1kHz at 0dB to all talkback outputs to assist channel identification and cabling checks.
There are two test tone modes, manual and auto.
To enable line-up tone mode: press and hold the rotary control and the group talk button
and channel 1 and 2 talk buttons for 5 seconds. The group talk button will flash amber to
indicate the line-up tone mode has been entered. The rotary control, group talk button and
talk buttons can now be released. By default, manual mode is enabled.
To switch between manual and auto tone modes: turn the rotary control one position in
either direction.
In manual line-up tone mode, press the talk buttons on each channel to route test tone to
the corresponding talkback output. Each talk button will illuminate amber when pressed.
When a button is released, the tone on that talkback output will be muted.
In auto line-up tone mode, each of the eight talkback outputs are automatically identified
by a unique number of short tone bursts, lasting 0.25 seconds each, which are repeated
every 5 seconds. Each talk button flashes amber to indicate when tone is being routed to
that channel, and the number of pulses corresponds to the channel number.
The 4W IN inputs function normally and any signal present is still routed to the loudspeaker
and headphone monitor outputs. This could be useful in allowing the user to receive
instructions on which channel to output tone to when using the test tone in manual mode.
To exit the line-up tone mode: press the rotary control once. The unit will then return to
normal operating mode.

8CM-TB8 8 Channel Talkback Control Unit User Handbook
REMOTES
REMOTES
5
Remotes
The two remote connectors on the rear panel provide a selection of remote inputs and
outputs. All of the remote outputs are on the Remotes 1 connector and are open collector
outputs, and all of the remote inputs are on the Remotes 2 connector and are active low.
Remotes 1 – Outputs
Pin1: Channel 1 Talk active – open collector output
Pin2: Channel 2 Talk active – open collector output
Pin3: Channel 3 Talk active – open collector output
Pin4: Channel 4 Talk active – open collector output
Pin5: Channel 5 Talk active – open collector output
Pin6: Channel 6 Talk active – open collector output
Pin7: Channel 7 Talk active – open collector output
Pin8: Channel 8 Talk active – open collector output
Pin9: Group Talk active – open collector output
Pin10: Loudspeaker Dim active – open collector output
Pin11: Loudspeaker Mute active – open collector output
Pin12: Channels 1-8 Audio Call active – open collector output
Pin13: Ground
Pin14: Ground
Pin15: Ground
The remote outputs are “tally”indicators and the talk active outputs indicate when any of
the channel talk or group talk buttons are active. The loudspeaker dim and mute outputs
indicate the state of the signal routed to the internal and external loudspeakers. The audio
call active remote output indicates when the signal level on one or more of the 4W IN
inputs is greater than -12dB.
Remotes 2 – Inputs
Pin1: Channel 1 Remote Call – active low input
Pin2: Channel 2 Remote Call – active low input
Pin3: Channel 3 Remote Call – active low input
Pin4: Channel 4 Remote Call – active low input
Pin5: Channel 5 Remote Call – active low input
Pin6: Channel 6 Remote Call – active low input
Pin7: Channel 7 Remote Call – active low input
Pin8: Channel 8 Remote Call – active low input
Pin9: Loudspeaker Dim enable – active low input
Pin10: Loudspeaker Mute enable – active low input
Pin11: no connection
Pin12: no connection
Pin13: Ground
Pin14: Ground
Pin15: Ground

CM-TB8 8 Channel Talkback Control Unit User Handbook 9
REMOTES
5
REMOTES
When a remote call is active, the corresponding talk button flashes amber. This call
condition takes priority over the audio level activated call input on each channel. The
loudspeaker mute input, when active, takes priority over the mute button operation.

10 CM-TB8 8 Channel Talkback Control Unit User Handbook
CONFIGURATION OPTIONS
CONFIGURATION OPTIONS
6
Configuration Options
The CM-TB8 has a wide range of user configurable options. These options are arranged in
sets, with an active set which contains the current working settings, and six configuration
set templates that allow settings to be stored and recalled at a later date. Two of the
configuration templates, sets 1 and 2, are read only and cannot be modified. The other
four, sets 3 to 6, can be used to store customised settings. This allows the unit to be
preconfigured for a range of user scenarios which can be instantly recalled. There are two
methods available for modifying the configuration settings, the on-board configuration
mode and the embedded web server. Any configuration settings that are changed using
either of these two methods only affect the active set.
On-Board Conguration Mode
The on-board configuration mode allows a limited number of configuration options in the
active set to be modified without the need of a PC. It also allows the active set to be saved
to one of the four editable sets, 3 to 6.
To enter the on-board configuration mode: press and hold the rotary control and channel
7 and 8 talk buttons for 5 seconds. The 2 talk level LEDs and the LS mute button LED will
flash red to indicate the configuration mode has been entered. The rotary control and talk
buttons can now be released.
There are four configuration options available in this mode and the MIC, Phantom and
HS LEDs illuminate red in sequence to indicate which option is currently being displayed.
Option 4 is shown when all three LEDs are illuminated. The value of the selected option
on a channel is shown by a sequence of recurring red flashes on the corresponding talk
button, one flash equals mode 1, two flashes equals mode 2 etc.
To cycle through the options: press the group talk button once. The MIC, Phantom and HS
LEDs will change to indicate which new option is being displayed.
To change the current option setting: press the corresponding talk button once. The
number of flashes will increase to indicate the new setting. Once the maximum option
mode setting has been reached, the value will wrap around to mode 1.
The on-board configuration mode options are listed below:
Option 1 – Channel inclusion in the group talk function (MIC LED is illuminated)
Mode 1 – channel is excluded from the group talk function
Mode 2 – channel is included in the group talk function
Option 2 – Channel IFB mode (Phantom LED is illuminated)
Mode 1 – 4W IN is IFB, Mic signal interrupts talkback signal when talk is active
Mode 2 – IFB A IN is IFB, Mic signal interrupts talkback signal when talk is active
Mode 3 – IFB B IN is IFB, Mic signal interrupts talkback signal when talk is active
Mode 4 – 4W IN is IFB, Mic signal is mixed with talkback signal when talk is active