Sonifex CM-CU1 User manual

Manufacturers of audio & video
products for radio & TV broadcasters
Commentator Units
CM-CU1 Commentator Unit for 1 Commentator & Line Input
CM-CU21 Commentator Unit for 2 Commentators & 1 Guest
HANDBOOK

CM-CU1 & CM-CU21 Handbook
This handbook is for use with the following product:
CM-CU1 Commentator Unit for 1 Commentator & Line Input
CM-CU21 Commentator Unit for 2 Commentators & 1 Guest
Stock Code: 30-239
Revision 2.04, November 2018
©Sonifex Ltd, 2018
All Rights Reserved
Sonifex Ltd, 61, Station Road, Irthlingborough,
Northants, NN9 5QE, England.
Tel: [phone]
Fax: [phone]
Email: [email protected]o.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.
Made in the UK by
For the latest Sonifex handbook information please visit the
Sonifex website at www.sonifex.co.uk

Contents
Contents
Product Warranty - 2 Year Extended i
Sonifex Warranty & Liability Terms & Conditions i
1. Definitions i
2. Warranty i
Unpacking Your Product ii
Repairs & Returns iii
Conformity iii
Safety & Installation of Mains Operated Equipment iii
Voltage Setting Checks iii
Fuse Rating iii
Power Cable & Connection iii
WEEE Directive iv
Atmosphere iv
1 CM-CU1 Commentator Unit 1
Introduction 1
CM-CU1 Main Panel Controls & Indicators 3
ON AIR Button 3
TALKBACK Buttons 4
Headphone Monitor Controls 4
PPM Meter Display 4
Limit LED 4
Power LED 4
CM-CU1 Front Panel Controls & Connections 5
Phantom Power Select Switch 5
Microphone Input Gain Controls 5
Headphone Output 5
Microphone Input 5
Line Input 5
CM-CU1 Rear Panel Controls & Connections 6
On Air Lock Controls 6
Talkback Controls 6
Limiter Controls 6
Test Tone Switch 7
Return Audio Inputs 7
Audio Outputs 7
DC Supply Input 7
GPIO Port 8
Mains Power 8
CM-CU1 Configuration Options 9
Entering Setup Mode 9
Changing The Current Page 9
Changing The Option Mode Setting 9
Config Page 1 - ON AIR Button Enable/Disable & TALKBACK Button
Latching Modes 9
Config Page 2 - Line Input Routing to Output 10
Config Page 3 - Commentator Mic & Line Input Routing to
Headphones 10
Config Page 4 - No Function 10
Config Page 5 - Limit LED Colour & Limit/Power LED Brightness 10
Config Page 6 - ON AIR/TALKBACK Button & PPM Brightness 10
Config Page 7 - Save/Load Configurations & Firmware Version 11
CM-CU1 Technical Specification 12
2 CM-CU21 Commentator Unit 15
Introduction 15
CM-CU21 Main Panel Controls & Indicators 17
On Air Buttons 17
Talkback Buttons 18
Headphone Monitor Controls 18
Commentator 3 Line Input Level Control 18
PPM Meter Display 18
Limit LED 18
Power LED 19
CM-CU21 Front Panel Controls & Connections 19
Phantom Power Select Switches 19
Microphone Input Gain Controls 19
Headphone Outputs 19
Microphone/Line Inputs 19
CM-CU21 Rear Panel Controls & Connections 20
On Air Lock Controls 20
Limiter Controls 20
Test Tone Switch 20
Talkback Controls 21
Return Audio Inputs 21
Audio Outputs 21
DC Supply Input 21
GPIO Port 22
Mains Power 22

Contents
CM-CU21 Configuration Options 23
Entering Setup Mode 23
Changing The Current Page 23
Changing The Option Mode Setting 23
Config Page 1 - ON AIR Button Enable/Disable & TALKBACK Button
Latching Modes 23
Config Page 2 - Line Input Routing to Output 24
Config Page 3 - Commentator Mic & Line Input Routing to
Headphones 24
Config Page 4 – Miscellaneous 25
Config Page 5 - Limit LED Colour & Limit/Power LED Brightness 25
Config Page 6 - ON AIR/TALKBACK Button & PPM Brightness 26
Config Page 7 - Save/Load Configurations & Firmware Version 26
CM-CU21 Technical Specification 28
Accessories 31
CM-TC1 Transport Case 31
Accessories continued... 32
Commentator Front Cover Plate 32

Figures
Figures
Fig 1-1: CM-CU1 Commentator Unit 1
Fig 1-2: CM-CU1 Commentator Unit Block Diagram 2
Fig 1-3: Top Panel View Of CM-CU1 3
Fig 1-4: Front Panel View Of CM-CU1 5
Fig 1-5: Rear Panel View Of CM-CU1 6
Fig 2-1: CM-CU21 Commentator Unit 15
Fig 2-2: CM-CU21 Commentator Unit Block Diagram 16
Fig 2-3: Top Panel View Of CM-CU21 17
Fig 2-4: Front Panel View Of CM-CU21 19
Fig 2-5: Rear Panel View Of CM-CU21 20
Fig 3-1a: CM-TC1 Commentator Unit Transport Case (Open
and Empty) 31
Fig 3-1b: CM-TC1 Commentator Unit Transport Case (Closed) 31
Fig 3-2: CM-CU21CP Commentator Unit Front Cover Plate 32

Warranty Registration
Sonifex Limited 61 Station Road Irthlingborough Northamptonshire NN9 5QE United Kingdom
Tel: [phone] Fax: [phone] Email: [e-mail] Internet: www.sonifex.co.uk
Register Online for an
Extended 2 Year Warranty
As standard, Sonifex products are
supplied with a 1 year back to base
warranty.
If you register the product online, you
can increase your product warranty
to 2 years and we can also keep
you informed of any product design
improvements or modifications.
To register your product, please go online to www.sonifex.co.uk/register
Product:
Serial No:

i
Warranty
Product Warranty - 2 Year Extended
As standard, Sonifex products are supplied with a 1 year back to base
warranty. In order to register the date of purchase and so that we can keep
you informed of any product design improvements or modifications, it is
important to complete the warranty registration online. Additionally, if you
register the product on the Sonifex website, you can increase your product
warranty to 2 years. Go to the Sonifex website at: http://www.sonifex.
co.uk/technical/register/index.asp to apply for your 2 year warranty.
Note: For your own records the product serial number is recorded on the
CE certification page of this handbook.
Sonifex Warranty & Liability Terms & Conditions
1. Definitions
‘the Company’ means Sonifex Ltd and where relevant includes companies
within the same group of companies as Sonifex Limited.
‘the Goods’ means the goods or any part thereof supplied by the Company
and where relevant includes: work carried out by the Company on items
supplied by the Purchaser; services supplied by the Company; and software
supplied by the Company.
‘the Purchaser’ means the person or organisation who buys or has agreed
to buy the Goods.
‘the Price’ means the Price of the Goods and any other charges incurred by
the Company in the supply of the Goods.
‘the Warranty Term’ is the length of the product warranty which is usually
12 months from the date of despatch; except when the product has been
registered at the Sonifex website when the Warranty Term is 24 months
from the date of despatch.
‘the Contract’ means the quotation, these Conditions of Sale and any
other document incorporated in a contract between the Company and the
Purchaser.
This is the entire Contract between the parties relating to the subject
matter hereof and may not be changed or terminated except in writing in
accordance with the provisions of this Contract. A reference to the consent,
acknowledgement, authority or agreement of the Company means in
writing and only by a director of the Company.
2. Warranty
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 the Warranty Term
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;

ii
Warranty
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);
(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.
Unpacking Your Product
Each product is shipped in protective packaging and should be inspected
for damage before use. If there is any transit damage take pictures of the
product packaging and notify the carrier immediately with all the relevant

iii
CE Conformity
details of the shipment. Packing materials should be kept for inspection and
also for if the product needs to be returned.
The product is shipped with the following equipment so please check to
ensure that you have all of the items below. If anything is missing, please
contact the supplier of your equipment immediately.
Item Quantity
Product unit 1
IEC mains lead fitted with moulded mains plug 1
Handbook and warranty card 1
If you require a different power lead, please let us know when ordering the
product.
Repairs & Returns
Please contact Sonifex or your supplier if you have any problems with your
Sonifex product. Email [e-mail] for the repair/
upgrade/returns procedure, or for support & questions regarding the
product operation.
Conformity
The products in this manual comply with the essential requirements of the
relevant European health, safety and environmental protection legislation.
The technical justification file for this product is available at Sonifex Ltd.
The declaration of conformity can be found at:
http://www.sonifex.co.uk/declarations
Safety & Installation of Mains
Operated Equipment
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. 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.
Voltage Setting Checks
Ensure that the machine operating voltage is correct for your mains power
supply by checking the box in which your product was supplied. The voltage
is shown on the box label. The available voltage settings are 115V, or 230V.
Please note that all products are either switchable between 115V and 230V, or
have a universal power supply.
Fuse Rating
The product 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 active fuse is fitted on the
outside rear panel of the unit.
Power Cable & Connection
An IEC power connector is supplied with the product which has a moulded
plug attached.
The mains plug or IEC power connector is used as the disconnect device.
The mains plug and IEC power connector shall remain readily operable to
disconnect the apparatus in case of a fault or emergency.
The mains lead is automatically configured for the country that the product is
being sent to, from one of:

iv
Safety & Installation
Territory Voltage IEC Lead Type Image
UK & Middle East 230V UK 3 pin to IEC lead
Europe 230V European Schuko round 2 pin to
IEC lead
USA, Canada and
South America 115V 3 flat pin to IEC lead
Australia & New
Zealand 230V Australasian 3 flat pin to IEC lead
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.
This apparatus is of a class I construction. It must be connected to a mains
socket outlet with a protective earthing connection.
Important note: If there is an earth/ground terminal on the rear panel of
the product then it must be connected to Earth.
WEEE Directive
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.
All products manufactured by Sonifex Ltd have the WEEE directive label
placed on the case. Sonifex Ltd will be happy to give you information about
local organisations that can reprocess the product when it reaches its “end
of use”, or alternatively all products that have reached “end of use” can be
returned to Sonifex and will be reprocessed correctly free of charge.
Atmosphere/Environment
This apparatus should be installed in an area that is not subject to excessive
temperature variation (<0°C, >50°C), moisture, dust or vibration.
This apparatus shall not be exposed to dripping or splashing, and no objects
filled with water, such as vases shall be placed on the apparatus.

1
CM-CU1 - Introduction 1
1 CM-CU1 Commentator Unit
Introduction
Fig 1-1: CM-CU1 Commentator Unit
The CM-CU1 Commentator Unit is a high quality, portable broadcast mixer
and 4-wire talkback unit. Its sturdy construction and flexibility of features
make it suitable for use in a wide variety of environments.
It provides a fully featured commentator position with both limited,
transformer balanced, and non-limited, electronically balanced outputs.
A limit indicator on the main panel shows when the adjustable limiter on
the mix output is active, and a bright 21 segment LED PPM meter, which
can be disabled, shows the main output level.
The line input can be configured to remain present at the
mix output even if the commentator is off air, making it
useful for routing crowd effects or pre-recorded material
to the programme feed. Its presence in the commentator’s
headphones is also configurable to suit the application.
Four talkback output channels, with a built in limiter, are
available to the commentator. They have adjustable gain
and can be linked to provide simultaneous operation.
A wide input gain range and switchable phantom power provides
support for a variety of microphone types, from high output
phantom units to low output ribbon microphones.
There are 5 transformer balanced return audio inputs which, along with
the commentator input, are routed to the headphone monitor controls.
With these headphone controls, any input can be level adjusted, and sent
to either the left, right or both ears.
A GPIO port gives an open-collector driven output indication of any active
on air or talkback channels, and four remote inputs provide an external
call/alert to each of the talkback controls.
The Commentator Unit has a built in line-up tone generator for easy
channel identification and cabling checks, and a flexible range of options
allow the unit to be customised to better suit the operational and users’
personal requirements.

2
1 CM-CU1 System Diagram
Fig 1-2: CM-CU1 Commentator Unit Block Diagram

3
CM-CU1 Mains Controls & Indicators 1
The main panel of the
Commentator Unit is split
into two areas. At the top
are the mix output PPM
meter display, mix output
limiter active indicator and
the power indicator LED.
Below this are the main
commentator position
controls, with the TALKBACK
and ON AIR buttons located
towards the bottom.
ON AIR Button
The ON AIR button
routes the commentator
microphone input signal to
the Comm Output and to
the Mix Output. This button
has a latching action; press
to activate and press again
to deactivate. When the
On Air control is active, the
button illuminates red and
the corresponding open
collector driver output on
the GPIO port is activated.
The line input signal is
permanently routed to the
mix output by default.
CM-CU1 Main Panel Controls & Indicators
Fig 1-3: Top Panel View Of CM-CU1

4
1 CM-CU1 Mains Controls & Indicators
It is possible to configure the line input signal to be routed only when the
ON AIR button is active. See Page 10 ‘Config Page 2 - Line Input Routing
to Output’ for details.
TALKBACK Buttons
The TALKBACK A, B, C and D buttons allow the commentator’s microphone
signal to
be redirected to the corresponding
Talkback Output. The commentator
output is muted and the commentator’s signal is removed from the Mix
Output.
The five return audio inputs Prog, A, B, C and D function normally when a
Talkback channel is active, allowing full-duplex communication between the
commentator and a third party. These buttons have a momentary action
by default; press to activate, release to deactivate. See Page 9 ‘Config
Page 1 - ON AIR Button Enable/Disable & TALKBACK Button Latching Modes’
for details of how to change the button action. When a Talkback control is
active, the button illuminates green and the corresponding open collector
driver output on the GPIO port is activated.
Headphone Monitor Controls
The commentator position has a set of six headphone controls which
allows it to monitor all of the units’ return audio and the commentator
and line inputs, if active. Each available input has an associated level
adjustment potentiometer and a headphone channel selector switch. Each
potentiometer provides a level adjustment from “full off” to “full on”, and
the headphone channel selector determines which ear the associated signal
is routed to; either the left, the right or to both ears when the switch is in
the centre position. By default, the commentator input signal is only routed
to the headphone monitor controls when the On Air control is active. It is
possible to route this signal to the headphones permanently, regardless of
the state of the On Air control line input. See Page 10 ‘Config Page 3 -
Commentator Mic & Line Input Routing to Headphones’ for details.
It is also possible to configure the presence of the line input signal in the
headphones using Config Page 3 too. By default, the line input signal is
permanently routed to the headphone monitor controls.
PPM Meter Display
The 21 segment LED PPM meter display indicates the level of the signal
on the Mix Output. The PPM scale conforms to IEC60268-10 11a and a dB
scale is also shown. There are options to set the brightness level of the PPM
meter, or it can be disabled if it is not required. See Page 10 ‘Config Page
5 - Limit LED Colour & Limit/Power LED Brightness’ for details.
Limit LED
The limit LED illuminates when the adjustable limiter on the Mix Output is
enabled and active. See Page 6 for information on the Limiter controls.
The colour and brightness level of the limit LED can be changed if required.
See Page 10 ‘Config Page 5 - Limit LED Colour & Limit/Power LED
Brightness’ for details.
Power LED
The power LED illuminates red to indicate that the unit has power from
either of its mains or DC inputs. If this indicator is not on when mains
power is connected to the unit, this may indicate a ruptured mains fuse
or a problem with the internal power supply module. The power LED also
indicates when the unit is in setup mode by flashing amber/red.

5
CM-CU1 Front Panel Controls & Connections 1
CM-CU1 Front Panel Controls & Connections
The front panel of the Commentator Unit has the commentator input and
headphone output as well as the microphone power and gain controls.
Phantom Power Select Switch
The commentator input supports phantom powered microphones. The
commentator position has a dedicated phantom power switch that enables
the 48V supply.
Microphone Input Gain Controls
The commentator microphone input has an adjustable gain setting. The
total gain range of +20dB to +86dB is split into two, to provide greater
accuracy of adjustment. The mic gain switch sets the base gain value of
either +20dB or +50dB for the input. The mic gain potentiometer can then
be adjusted to add up to 36dB of additional gain.
Headphone Output
The front panel mounted headphone output is via a ¼” stereo jack socket,
which is locking to prevent the headphone plug from being accidentally
pulled out.
Fig 1-4: Front Panel View Of CM-CU1
Microphone Input
The microphone input is via a 3 pin female XLR-3 connector with the
following connections:
Pin 1: Ground
Pin 2: Phase
Pin 3: Non-phase
Line Input
The line input is via a 3 pin female XLR-3 connector with the following
connections:
Pin 1: Ground
Pin 2: Phase
Pin 3: Non-phase

6
1 CM-CU1 Rear Panel Controls & Connections
CM-CU1 Rear Panel Controls & Connections
The rear panel of the Commentator Unit carries the five return audio inputs
and commentator, talkback and mix output connectors. Four additional
controls are located on the rear panel; On Air Lock, Talkback Gang, Limiter
and Test Tone.
On Air Lock Controls
The On Air Lock prevents the commentator’s ON AIR button from being
deactivated accidentally. When the On Air Lock is enabled, the on air
channel can only be deactivated by first pressing the pushbutton located
next to the On Air Lock switch. A slot in the rear panel makes locating the
On Air Lock pushbutton easy; simply position your finger in the slot in the
rear panel, indicated by the “ON AIR LOCK” text on the top panel, then slide
your finger down the slot until you reach the pushbutton.
Fig 1-5: Rear Panel View Of CM-CU1
Talkback Controls
The TALKBACK GANG switch links the operation of each of the
commentator’s TALKBACK A, B, C and D buttons. When this switch is on,
pressing one of the TALKBACK buttons automatically activates the other
TALKBACK buttons. Up to an additional 12dB of gain is available on all
talkback outputs, if required. This is applied prior to the limiter and is
adjusted using the rear panel GAIN potentiometer.
Limiter Controls
The LIMITER ON/OFF switch and LEVEL potentiometer control the limiter
that is applied to the Mix Output. The potentiometer sets the threshold
level at which the limiter becomes active, and has a range of between
-13dB to the maximum output level of +25dB.

7
CM-CU1 Rear Panel Controls & Connections 1
Test Tone Switch
The CM-CU1 has a built in test tone generator which selectively routes
a line-up tone to all outputs to assist channel identification and cabling
checks. There are two test tone modes; manual and auto. Regardless of
mode, a 1kHz tone is permanently routed to the Mix Output and the PPM
meter will indicate that the signal level is 0dBu. The test tone is enabled
by sliding the TEST TONE switch to the upper “ON” position. To change the
test tone mode; keep the Talkback B and Talkback C buttons pressed for 2.5
seconds.
Test Tone Manual Mode
With the test tone in manual mode, the ON AIR and TALKBACK buttons flash
amber. The test tone can be routed to the Comm and Talkback Outputs
by pressing the ON AIR or corresponding TALKBACK buttons. The ON AIR
button illuminates red when pressed and the TALKBACK buttons illuminate
green. When the button is released, the tone on that output is muted.
Test Tone Auto Mode
With the test tone in auto mode, each of the Comm and Talkback outputs
are automatically identified by a unique number of short tone bursts,
lasting 0.25 seconds each, which are repeated every 3 seconds. Each
button flashes when tone is being routed to the corresponding output. The
number of pulses on each output is shown below:
Comm 1 pulse
Talkback A 2 pulses
Talkback B 3 pulses
Talkback C 4 pulses
Talkback D 5 pulses
The 5 return audio inputs function normally when the test tone is enabled.
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. When
the test tone is disabled, normal operating mode is resumed and the On Air
and Talkback buttons return to the state they were in prior to entering test
tone mode.
Return Audio Inputs
The five transformer balanced return audio inputs, Prog, A, B, C and D are
via 3 pin female XLR-3 connectors with the following connections:
Pin 1: Ground
Pin 2: Phase
Pin 3: Non-phase
Audio Outputs
The electronically balanced commentator output, and the transformer
balanced talkback A, B, C and D and mix outputs are all via 3 pin male XLR-3
connectors with the following connections:
Pin 1: Ground
Pin 2: Phase
Pin 3: Non-phase
DC Supply Input
The commentator unit can be powered from an external, regulated 12V or
24V DC power source. The DC input is via a 4 pin male XLR-4 connector with
the following connections:
Pin 1: 0V
Pin 2: No connection
Pin 3: No connection
Pin 4: +VE (12-24 Volt DC)
When powering the CM-CU1 via the DC supply input, it is important to
ensure that the unit is suitably earthed. An earth connection point is
provided on the rear panel in the form of a M4 stud and screw and this
should be connected directly to a technical earth.

8
1 CM-CU1 Rear Panel Controls & Connections
GPIO Port
The CM-CU1’s GPIO port has 5 open-collector driven outputs and 4 active
low inputs. The open-collector outputs, which are low (conducting) when
active, indicate which of the On Air or Talkback channels are active.
Each of the 4 active low inputs drives a call/alert signal on the
corresponding Talkback button. When an input is active, the associated
TALKBACK button flash amber.
The GPIO port connector is a 15-way female D-type with the following pin
assignments:
Pin Number I/O Function
1 O Commentator ON AIR active – open collector output
2 O TALKBACK A active – open collector output
3 O TALKBACK B active – open collector output
4 O TALKBACK C active – open collector output
5 O TALKBACK D active – open collector output
6 - Digital ground (0V)
7 - Digital ground (0V)
8 - No connection
9 - Digital ground (0V)
10 ITALKBACK A call/alert – active low input
11 ITALKBACK B call/alert – active low input
12 -Digital ground (0V)
13 ITALKBACK C call/alert – active low input
14 ITALKBACK D call/alert – active low input
15 - Digital ground (0V)
Mains Power
Mains power is applied via a standard three-pin IEC male socket. Mains
voltages between 85V and 264V AC at frequencies between 47 and 63Hz
are accepted without adjustment.
A 1A, 5 x 20mm SB fuse is used. The Earth pin MUST be connected to
ensure safety.

9
CM-CU1 Configuration Options 1
CM-CU1 Configuration Options
The CM-CU1 has several user configurable options that can be changed to
suit specific operational or personal requirements. These options can only
be changed by entering a setup mode, which is accessible when the unit is
powered-up.
Entering Setup Mode
Apply power to the unit whilst keeping the TALKBACK A and TALKBACK B
buttons pressed for 5 seconds. The power indicator LED will flash red and
amber to indicate that Setup Mode has been entered. The TALKBACK A and
TALKBACK B buttons can now be released.
The configuration options are arranged in 7 pages, with up to 5 options in
each page. The current page number is indicated on the PPM display by a
single illuminated segment, e.g. segment 5 illuminated means that you are
on Page 5.
Each option within the selected page is associated with one of the 5 main
control buttons on the top panel of the unit. Each button flashes in a
recurring sequence to indicate the current mode setting of the associated
option. One flash equals mode 1, two flashes equals mode 2 etc. Buttons
that do not have an associated option in the current page do not flash.
Please Note: when Page 6 is selected, all the segments in the PPM display
are enabled to indicate the current PPM illumination level setting.
Changing The Current Page
Press and hold the ON AIR button for at least 1 second. The PPM display will
change to indicate the new page.
Changing The Option Mode Setting
Press the appropriate button once. The number of flashes increases to
indicate the new mode setting. Once the maximum option mode setting
has been reached, the value wraps around to mode 1.
The configuration option settings for each page are listed below. The factory
default settings for each option are shown in brackets:
Config Page 1 - ON AIR Button Enable/Disable & TALKBACK
Button Latching Modes
ON AIR button:
Mode 1 ON AIR is permanently disabled and cannot be selected.
Mode 2 ON AIR can be selected as normal (default).
Mode 3 ON AIR is permanently selected and cannot be disabled.
TALKBACK A button:
Mode 1 TALKBACK A button momentary mode enabled (default).
Mode 2 TALKBACK A button latching mode enabled.
Mode 3 TALKBACK A button momentary and latching modes enabled.
TALKBACK B button:
Mode 1 TALKBACK B button momentary mode enabled (default).
Mode 2 TALKBACK B button latching mode enabled.
Mode 3 TALKBACK B button momentary and latching modes enabled.
TALKBACK C button:
Mode 1 TALKBACK C button momentary mode enabled (default).
Mode 2 TALKBACK C button latching mode enabled.
Mode 3 TALKBACK C button momentary and latching modes enabled.
TALKBACK D button:
Mode 1 TALKBACK D button momentary mode enabled (default).
Mode 2 TALKBACK D button latching mode enabled.
Mode 3 TALKBACK D button momentary and latching modes enabled.
Please Note:
Momentary mode button operation – press to activate, release to
deactivate. Latching mode button operation – press once to activate, press
again to deactivate. Momentary and latching mode button operation - for
momentary press the button for less than 0.25 sec, for latching press for
more than 0.25 sec.

10
1 CM-CU1 Configuration Options
Config Page 2 - Line Input Routing to Output
ON AIR button:
Mode 1 Line input permanently routed to Mix Output (default).
Mode 2 Line input is permanently unrouted to Mix Output.
Mode 3 Line input routed to Mix Output only when ON AIR is active.
TALKBACK A, B, C & D buttons:
No associated option on this page.
Config Page 3 - Commentator Mic & Line Input Routing to
Headphones
ON AIR button:
Mode 1 Commentator input permanently routed to Commentator
headphones.
Mode 2 Commentator input routed to Commentator headphones
only when ON AIR is active (default).
TALKBACK A button:
Mode 1 Line input routed to Commentator headphones only when
ON AIR is active (provided line input is not permanently
unrouted to mix output).
Mode 2 Line input permanently routed to Commentator headphones
(default).
TALKBACK B, C & D buttons:
No associated option on this page.
Config Page 4 - No Function
ON AIR button & TALKBACK A, B, C & D buttons:
No associated option on this page.
Config Page 5 - Limit LED Colour & Limit/Power LED Brightness
ON AIR button:
Mode 1 Limit indicator illuminates blue when active (default).
Mode 2 Limit indicator illuminates green when active.
Mode 3 Limit indicator illuminates red when active.
Mode 4 Limit indicator illuminates white when active. This setting
can be used when a brighter limit indication is required.
TALKBACK A button:
Mode 1 Power and limit indicator brightness level 1 (minimum
brightness).
Mode 2 Power and limit indicator brightness level 2.
Mode 3 Power and limit indicator brightness level 3 (default).
Mode 4 Power and limit indicator brightness level 4.
Mode 5 Power and limit indicator brightness level 5.
Mode 6 Power and limit indicator brightness level 6.
Mode 7 Power and limit indicator brightness level 7.
Mode 8 Power and limit indicator brightness level 8 (maximum
brightness).
TALKBACK B, C & D buttons:
No associated option on this page.
Config Page 6 - ON AIR/TALKBACK Button & PPM Brightness
ON AIR button:
Mode 1 ON AIR and TALKBACK button brightness level 1 (minimum
brightness).
Mode 2 ON AIR and TALKBACK button brightness level 2.
Mode 3 ON AIR and TALKBACK button brightness level 3.
Mode 4 ON AIR and TALKBACK button brightness level 4.
Mode 5 ON AIR and TALKBACK button brightness level 5.
Mode 6 ON AIR and TALKBACK button brightness level 6.
Mode 7 ON AIR and TALKBACK button brightness level 7 (maximum
brightness) (default).