bel Digital Audio BM-AV3S User Manual

BM-AV3S

A/V monitor system

User’s Guide Version 1.4 2/10/2009

BEL DIGITAL AUDIO BM-AV3S

BEL (Digital Audio) Ltd. has made every effort to ensure the accuracy of information contained within this document which is nevertheless supplied for information purpo ses only and does not constitute any form of warranty or guarantee.

All trademarks acknowledged. The information in this document is subject to change without notice.

Bel (Digital Audio) Ltd. Unit 3 Horwood Court Bletchley Milton Keynes Bucks MK11RD UK

Tel: +44 ( 0) 1908 641063 Email: info@beldigital.com Web: www.beldigital.com

BEL DIGITAL AUDIO BM-AV3S

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INTRODUCTION 1

Main features 1

OPERATION 3

S

ELECTING SOURCES 3

B

ARGRAPH SCALES 4

INSTALLATION 5

CONNECTOR I/O 5

RS232 Host interface connector pinout 6

CONFIGURATION 7

Adjusting analog input level 8 Adjusting audio monitor output level 9 Adjusting bargraph break-points and ballistics 10 Inserting bargraph graticules 13

USING MONITORMX SOFTWARE 14

Main Features 14

MONITORMX SOFTWARE OPERATION 15

Running MonitorMx software for the first time 15 Viewing connected frames 15 Configuring alarms 16 Source selection 17 Meter characteristics 17 Disabling local control 17

MONITORMX SOFTWARE INSTALLATION 18

Minimum pre-requisites: 18 Serial cable 18

BM-AV3 SERIAL PROTOCOL 20

OVERVIEW 20

Frame format 20

COMMANDS 22 DATA FORMATS 23

PROBLEM SOLVING 28

BEL DIGITAL AUDIO BM-AV3S

Sample problems and their solutions 29

SPECIFICATIONS 30

BEL DIGITAL AUDIO BM-AV3S Introduction

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The BM-AV3S is a professional audio and video monitor system housed in a 3U rack.

The unit features two speakers, a high quality seven inch TFT video display and an analogue line output. Audio input signals can be in the form of analog, AES (SPDIF) and SDI embedded data. The BM-AV3S accepts audio inputs in groups of 4 channels from the selected source and can direct any two from these to the speakers. Video input signals can be selected from a pair of SDI inputs or an analog composite input.

Main features

• 2 x SDI and 1 x composite video inputs with seven inch TFT colour video display

• Auto PAL/NTSC detection

• SDI embedded (groups 1 – 4), 2 x AES and 2 x analog audio input pairs

• Option for balanced XLR or unbalanced BNC digital audio I/O

• High-quality, high SPL audio reproduction with soft limiting

• 4 x tri-colour bargraphs with six standard scales and ballistics, adjustable colour

transition points and peak-hold facility

• Line level analog audio output of sources directed to loudspeakers

• Audio follow video facility

• Selected SDI source converted to analog composite video for convenient monitoring

• Headphone connector with speaker mute

• Individually user-calibrated audio level inputs/outputs and metering

• Windows GUI and separate RS232 protocol for remote control of all alarm functions

and audio/video switching

BEL DIGITAL AUDIO BM-AV3S Introduction

The BEL Digital BM-AV3S

All audio inputs are converted to 24 bit digital form and AES inputs are re-sampled using sample rate converters where necessary at an internally generated 48 kHz. If embedded audio from a serial digital video input is selected, the sampling clock recovered from this is used instead.

The audio source switch selects which audio source is available to the speaker sele ctors and bargraphs.

The left and right speaker switches select which of the currently selected four audio channels is available at the speakers after three stages of analog processing.

The selected audio is first passed through factory preset equalization filters. Then electronic level control is then applied with the balance and volume knobs providing control voltages. Finally a soft limiter is used to protect the speakers. The headphone output is taken before the limiters and mutes the speakers when used.

A soft mute is applied to the audio when any select switches are used to reduce glitches.

BEL DIGITAL AUDIO BM-AV3S Operation

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The front panel user interface consists of 6 rotary controls, a menu button, a TFT display and four bargraphs. In addition there is a headphone output, two LEDs for sustained anti-phase, and five status LEDS.

The BM-AV3S front control panel

Selecting sources

The audio source switch selects which group of audio sources is available to the spea ker selectors and bargraphs. The possible choices are analog, AES A + B, embedded groups 1 to 4 from either SDI1 or SDI2 or Audio Follow Video (AFV). The video source switch determines which SDI input audio is de-embedded from.

The AFV position establishes the follow mode, where the audio is automatically selected depending on the position of the video source switch. For example, composite video selection will cause analog audio to be selected, SD1 will allow group 1 of the SDI1 serial digital input to be monitored and SD2 will monitor group 1 from the SDI2 serial digital video input.

The REM or remote position of the video source switch forces BM-AV3S to be controlled from the serial port. Any serial commands will then take precedence over the front control panel.

The image displayed on the TFT can be adjusted by pressing the menu button and then following the on screen instructions.

Note:

If an SDI video source is selected using the video source switch, that input will provide de-embedded audio. If the video source switch is in the composite position (or REM with no active remote video selection) and an SDI audio source is selected, then audio groups 1 to 4 are taken from SDI1.

BEL DIGITAL AUDIO BM-AV3S Operation

Bargraph scales

The following bargraph ballistics may be selected using internal switche s.

Scale type

Range Attack Fallback AES/EBU: 60 dB (0 to -60 dB) 1ms 1.5 Sec per 20 dB decay DIN PPM: 55 dB (+5 to -50 dB) 10 ms 1.5 Sec per 20 dB decay VU: 23 dB (+3 to -20 dB) 300 ms 300 ms BBC PPM: +12 to-12 dB - mark 7 to 1 10 ms 2.85 Sec - mark 7 to 1 VU EXT: 80 dB (+20 to -60 dB) 300 ms 300 ms NORDIC: 54 dB (+12 to -42 dB) 5 ms 1.7 Sec per 20 dB decay

BM-AV3S scale ballistics

Stick-on scale graticules, which may be applied to the space between the front-panel bargraphs, are supplied with the machine.

BM-AV3S scale graticules

Note:

Bargraph colour transition points and peak hold decay may also be adjusted internally.

Refer to the Configuration chapter for switch settings and graticule fitting instructions.

BEL DIGITAL AUDIO BM-AV3S Installation

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The BM-AV3S 3U frame may be installed in 19 inch bays with 300 mm depth including typical cable and connector depth. Ventilation is by natural convection and there are vents at each side and on the top and bottom covers of the unit.

Frames may be installed into bays, providing airflow through these vents is not impeded.

Connector I/O

All connections, with the exception of the headphone socket, are provided on the rear panel of the frame. Video inputs and outputs use BNC connectors and all data connectors use 9 way ‘D’ type connectors.

The BM-AV3S balanced audio version rear view

Digital audio I/O may be supported with either XLR connectors for balanced audio or BNCs for unbalanced audio, depending on the BM-AV3S version.

BEL DIGITAL AUDIO BM-AV3S Installation

RS232 Host interface connector pinout

Connector type: 9 way D female Speed: 9600 bps Format: 8 bit, no parity, 2 stop bits

Description

1

Not connected

2

Rx (from host)

3

Tx (to host)

4

Not connected

5

GND

6

Not connected

7

Not connected

8

Not connected

9

Not connected

Note:

A null-modem lead will be required to interface to a PC. See the MonitorMx software chapter for more details.

BEL DIGITAL AUDIO BM-AV3S Configuration

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Access to BM-AV3S internal adjustments is obtained with the top removed.

BM-AV3S internal adjustments

The following adjustments may be made:

• Monitor output level – SW3/potentiometers main board

• Analog input level – SW4 and SW5/potentiometers main board

• Bargraph settings – SW1 and SW2 main board, near power supply

Warning:

Configuration instructions are for trained personnel. To avoid risk of dangerous electric shock, do not remove any covers or carry out adjustments unless qualified to do so.

BEL DIGITAL AUDIO BM-AV3S Configuration

Adjusting analog input level

In the following tables, ON is obtained with a switch lever in the DOWN position. The adjustments are located on the main board under the output sub-board.

Analog input adjustments – 0 dB setting shown

SW4

Anlg Input

Setting when ON

1

1 0 dB (0 dBu in = 0 on analog scale)

2

1 4 dB (+4 dBu in = 0 on analog scale)

3

1 8 dB (+8 dBu in = 0 on analog scale)

4

1 Variable – adjacent pot* –10 to +12 dB

5

2 0 dB (0 dBu in = 0 on analog scale)

6

2 4 dB (+4 dBu in = 0 on analog scale)

7

2 8 dB (+8 dBu in = 0 on analog scale)

8

2 Variable – adjacent pot* –10 to +12 dB

SW5

Anlg Input

Setting when ON

1

3 0 dB (0 dBu in = 0 on analog scale)

2

3 4 dB (+4 dBu in = 0 on analog scale)

3

3 8 dB (+8 dBu in = 0 on analog scale)

4

3 Variable – adjacent pot* –10 to +12 dB

5

4 0 dB (0 dBu in = 0 on analog scale)

6

4 4 dB (+4 dBu in = 0 on analog scale)

7

4 8 dB (+8 dBu in = 0 on analog scale)

8

4 Variable – adjacent pot* -10 to +12 dB

Note:

It is intended that only one switch lever is set ON for each analog input. The ON position is obtained with a switch lever in the direction of the arrow

(downward in the above drawing). *Clockwise rotation increases gain.

BEL DIGITAL AUDIO BM-AV3S Configuration

Adjusting audio monitor output level

In the following tables, ON is obtained with a switch lever in the DOWN position. The adjustments are located on the main board under the output sub-board.

Analog monitor output adjustments – 0 dB setting shown

SW3

Monitor Output

Setting when ON

1

Left 0 dB (0 on analog scale = 0 dBu on output)

2

Left 4 dB (0 on analog scale = +4 dBu on output)

3

Left 8 dB(0 on analog scale = +8 dBu on output)

4

Left Variable – adjacent pot* 0 to +12 dB

5

Right 0 dB (0 on analog scale = 0 dBu on output)

6

Right 4 dB (0 on analog scale = +4 dBu on output)

7

Right 8 dB(0 on analog scale = +8 dBu on output)

8

Right Variable – adjacent pot* 0 to +12 dB

Note:

It is intended that only one switch lever is set to ON for each monitor output. The ON position is obtained with a switch lever in the direction of the arrow

(downward in the above drawing). *Clockwise rotation increases gain.

BEL DIGITAL AUDIO BM-AV3S Configuration

Adjusting bargraph break-points and ballistics

The adjustments, SW1 and SW2 are located near the power supply.

BM-AV3S bargraph adjustments

SW1-8

AES to analog adjust

OFF ON

-18 dBFS = 0 on analog scale

-20 dBFS = 0 on analog scale

The –18 dB and –20 dB settings define the correspondence between AES input level and the 0 mark on an analog scale. This allows analog scales to be used with digital signals.

Note:

When digital inputs are used with an analogue scale the line outputs will be less than that indicated on the meters since the digital to analogue converters clip at +15 dB. The effective loss is -3 dB when the 18 dB position is selected and -5 dB when the 20 dB position is selected.

SW1-7 SW1-6

Peak hold decay

OFF OFF None (Off) OFF ON 3 seconds ON OFF 7 seconds ON ON Indefinite

SW1-5 SW1-4 SW1-3

Scale type

OFF OFF OFF AES OFF OFF ON DIN OFF ON OFF VU OFF ON ON BBC ON OFF OFF Extended VU ON OFF ON NORDIC ON ON OFF No scale ON ON ON No scale

Note:

The OFF position is obtained with a switch lever in the direction of the arrow, (to the right in the above drawing).

BEL DIGITAL AUDIO BM-AV3S Configuration

Each bargraph has 53 tri-colour segments. The top and bottom segments are reserved leaving 51. Up to 31 of the remaining top most segments may be coloured red. Up to 31 of segments from the end of the red zone downward may be coloured amber. The remaining segments (if any) are always green.

Choosing how many segments are coloured red from the top of the bargraph sets the ‘red zone’. Select from none to 31 using SW1-2, SW1-1, SW2-8, SW2-7 and SW2-6 as follows:

SW1-2 SW1-1 SW2-8 SW2-7 SW2-6

Segment from bargraph top

OFF OFF OFF OFF OFF None OFF OFF OFF OFF ON 1 OFF OFF OFF ON OFF 2 OFF OFF OFF ON ON 3 OFF OFF ON OFF OFF 4 OFF OFF ON OFF ON 5 OFF OFF ON ON OFF 6 OFF OFF ON ON ON 7 OFF ON OFF OFF OFF 8 OFF ON OFF OFF ON 9 OFF ON OFF ON OFF 10 OFF ON OFF ON ON 11 OFF ON ON OFF OFF 12 OFF ON ON OFF ON 13 OFF ON ON ON OFF 14 OFF ON ON ON ON 15 ON OFF OFF OFF OFF 16 ON OFF OFF OFF ON 17 ON OFF OFF ON OFF 18 ON OFF OFF ON ON 19 ON OFF ON OFF OFF 20 ON OFF ON OFF ON 21 ON OFF ON ON OFF 22 ON OFF ON ON ON 23 ON ON OFF OFF OFF 24 ON ON OFF OFF ON 25 ON ON OFF ON OFF 26 ON ON OFF ON ON 27 ON ON ON OFF OFF 28 ON ON ON OFF ON 29 ON ON ON ON OFF 30 ON ON ON ON ON 31

Note:

It is not possible to set 31 red and 31 amber segments, since there are only 51 segments for level display purposes.

BEL DIGITAL AUDIO BM-AV3S Configuration

Choosing how many segments are coloured amber from the end of ‘red zo ne’ sets the ‘amber zone’. Select from none to 31 using SW2-5, SW2-4, SW2-3, SW2-2 and SW2-1 as follows:

SW2-5 SW2-4 SW2-3 SW2-2 SW2-1

Segment from last RED ZONE

OFF OFF OFF OFF OFF None OFF OFF OFF OFF ON 1 OFF OFF OFF ON OFF 2 OFF OFF OFF ON ON 3 OFF OFF ON OFF OFF 4 OFF OFF ON OFF ON 5 OFF OFF ON ON OFF 6 OFF OFF ON ON ON 7 OFF ON OFF OFF OFF 8 OFF ON OFF OFF ON 9 OFF ON OFF ON OFF 10 OFF ON OFF ON ON 11 OFF ON ON OFF OFF 12 OFF ON ON OFF ON 13 OFF ON ON ON OFF 14 OFF ON ON ON ON 15 ON OFF OFF OFF OFF 16 ON OFF OFF OFF ON 17 ON OFF OFF ON OFF 18 ON OFF OFF ON ON 19 ON OFF ON OFF OFF 20 ON OFF ON OFF ON 21 ON OFF ON ON OFF 22 ON OFF ON ON ON 23 ON ON OFF OFF OFF 24 ON ON OFF OFF ON 25 ON ON OFF ON OFF 26 ON ON OFF ON ON 27 ON ON ON OFF OFF 28 ON ON ON OFF ON 29 ON ON ON ON OFF 30 ON ON ON ON ON 31

BEL DIGITAL AUDIO BM-AV3S Configuration

Inserting bargraph graticules

The following bargraph scale graticules are supplied with each BM-AV3S:

BM-AV3S scale graticules

To apply a graticule proceed as follows:

• peel back the protective backing from the chosen graticule

• apply the graticule to the space between a pair of bargraphs

• repeat the process for the other bargraph graticule position

• ensure that the bargraph setting matches the graticule

• adjust the colour transitions and peak hold decay as desired

BEL DIGITAL AUDIO BM-AV3S Using MonitorMx software

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The MonitorMx remote control and status software has been provided to ease the task of operating and monitoring one or more BM-AV3 units from remote locations.

Main Features

• Fifteen alarm categories

• Signal presence

• Support for multiple BM-AV3 units

• Automatic model detection and custom unit names

• Reads selected meter ballistics

• Full editing of scale transition points and peak hold characteristics

• Visual and aural alarms

• Individual and system alarm reset

• Disable option for local controls

The MonitorMx software will run on Windows 98 Second Edition, Windows NT4. Windows 2000 and XP. It will not run on Windows 95 or Windows 98 First Edition.

BEL DIGITAL AUDIO BM-AV3S Using MonitorMx software

MonitorMx software operation

The MonitorMx application provides monitoring of video and audio alarm status for any local BM-AV3 frame or multiple-frame system.

MonitorMX main screen

Running MonitorMx software for the first time

The MonitorMx software will search automatically for BM-AV3 frames connected to the serial ports of the PC the software is running on when the application loads. The Alarms Present indicator will illuminate red if any of the connected frames are generating alarms. Individual alarms and alarm configuration will only be shown for selected frames.

MonitorMx will not interrogate or connect to frames on a network.

Viewing connected frames

To view connected frames use the unit select box or select List Devices under the view menu.

BEL DIGITAL AUDIO BM-AV3S Using MonitorMx software

Configuring alarms

To enable alarms on a selected BM-AV3 frame, check the alarm categories at the left of the main screen. Toggle inverts the selection. If an alarm is generated the associated virtual LED will change from green to red and will flash if the Flashing box has been checked. If PC Sounder has been checked an audio alert will also be sent to a sound card a nd any connected speakers if fitted.

System alarms

The Systems Alarms command under the View menu will bring up the systems alarms window.

The MonitorMX system alarms

System alarms are alarms generated by any connected frame. Controls are provided to reset alarms from all frames and to enable visual alarm flashing and audible alerts for alarms generated from any connected frames.

Resetting alarms

Alarms are not automatically cancelled when a monitored signal is restored to normal. To cancel alarms click on a Reset button for an individual frame or for all frames using the Reset button in the Systems Alarms window.

Muting alarms

An audio alert in the form of a .wav file can be sent to any sound card and connected speakers. Mute the alarm by un-checking the PC Sounder box for an individual frame or for all frames using the Systems Alarms window.

Notes:

Un-checking the PC Sounder box does not affect audible alarms on any BM-AV3 frame(s).

The selective SET function of the front control panel is not required, since any alarm may be selected individually.

BEL DIGITAL AUDIO BM-AV3S Using MonitorMx software

Source selection

The source selection check boxes will only function if the Video Source switch on the selected unit’s front panel is in the REM (remote) position. The source selection is the same as that obtained at the front control panel with the addition of a colour bar test signal. Selecting colour bars does not affect the current audio source selection.

Meter characteristics

The meter type, peak hold time and the digital to analog reference setting are read when the software loads and can only be changed from the internal switches in the BM-AV3 frame.

Colour transitions

Each bargraph has 53 tri-colour segments. The top and bottom segments are reserved a s alarm indicators leaving 51. Up to 31 of the remaining top most segments may be coloured red. Up to 31 of segments from the end of the red zone downward may be coloured amber. The remaining segments (if any) are always green.

The red and amber sections of the selected bargraph scale may be adjusted by changing the values in the spin boxes provided. Be careful not to erase red zone segments with the amber control.

Tip:

Use the Off-line mode to make configuration changes. Click apply or go online when ready.

Disabling local control

The local controls of a selected frame may be disabled by checking the ‘Disa ble Local Control’ check box.

BEL DIGITAL AUDIO BM-AV3S Using MonitorMx software

MonitorMx software installation

The MonitorMx Remote Control and Status software is designed for the Bel Series of professional audio and video monitor units.

The MonitorMx software MUST run on the same PC that the BM-AV3 unit(s) are physically connected to.

Minimum pre-requisites:

• A PC with Windows 98 Second Edition, NT4 with SP 5 or higher or Windows 2000

• An RS232 serial connection from the PC to at least one BM-AV3 frame

• A sound card and connected speakers to hear the audio alert siren .wav file

Notes:

Additional serial ports (up to four in total) may be required on the host PC for additional frames.

Serial cable

Null-Modem cable from BM-AV3 RS232 port to PC RS232 port

BM-AV3 RS232 9 pin female ‘D’ connector

RS232 PC port 9 pin female ‘D’ connector

RS232 PC port 25 pin

female ‘D’ connector 2 (Rx) 3 (Tx) 5

3 2 5

2

3

7

Note:

A standard screened null-modem cable should be adequate however pin numbers not shown, do not need to be wired. The screen is normally wired to ground via the ‘D’ connector metalwork.

To install the MonitorMx software proceed as follows:

• To view all of the application window, set graphics resolution to at least 800 x 600

• Remove any previous version of the software using the Add/Remove Programs

application in the Windows Control Panel

• Insert the supplied CD and the installation should start immediately – if it does not, run the setup.exe file on the CD

• Obey any installation program prompts and restart the PC if prompted

BEL DIGITAL AUDIO BM-AV3S Using MonitorMx software

If successful, the installation program will install a BEL Digital program group. Run the program from the program group using Start>Programs>BEL Digital>MonitorMx. Please see the Operation chapter for an explanation of program features.

BEL DIGITAL AUDIO BM-AV3S BM-AV3 serial protocol

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Overview

Commands to be communicated to the remote unit (BM-AV3) are arranged in frames. The se frames will then be sent to the remote unit, which will always reply with either ACK for acceptance or NAK for rejection. Any requested reply then follows in the same frame format.

Frame format

The frame starts with a start character 0xAA (alternating ones and zeros). This i s followed by the destination address, the source address, the command code, the data count, the data, a checksum and an end flag 0xFE.

Start Flag 0XAA Destination Address Source Address Command Data Count Data Checksum End Flag 0XFE

Start Flag:

The start flag 0XAA may be sent at any time. If sent during a frame this will cause the frame to effectively restart.

Destination Address:

This should be set to 1.

Source Address:

This should be set to 1.

Command:

This character is the command for the remote unit and must fall in the range 0X80 to 0XEF. More details of the relevant codes are shown below.

BEL DIGITAL AUDIO BM-AV3S BM-AV3 serial protocol

Data count:

This is the total number of data bytes following, up to a maximum of 127.

Data:

The data required for the command is carried here. Each character can have a value of 0X00 to 0X7F i.e. 7 bits.

Checksum:

This is the modulo sum of the characters in the frame between the destination address and the last data character inclusively. It is calculated thus:

DO { checksum = (character+checksum) AND 0x7F } FOR ALL CHARACTERS IN FRAME.

End Flag:

A character 0XFE ends the frame.

BEL DIGITAL AUDIO BM-AV3S BM-AV3 serial protocol

Commands

Commands from the remote controller to the BM-AV3S.

Code(Hex) Function Reply 80

General prompt for a reply C0 - ACK (OK)

C1 - NAK (send again)

81

Use first data char as a second command ACK

82

Request unit identifier C2.

83

Set up switches Data count =5 See below for format ACK

84

Set up alarm functions Data count=2 See below for format ACK

85

Request Detail C5

86

Request Switches C6

Replies

Replies, when requested (e.g. 82), will consist of frames that contain the original command value plus 0X40. So a request for an ident, 0x82, will elicit a reply of a frame containing 0xC2 and the ident string. (BM-AV3S Vn.n)

BEL DIGITAL AUDIO BM-AV3S BM-AV3 serial protocol

Data formats

General Prompt (0x80)

This command will cause the BM-AV3 to respond with an ACK or NACK reply. It can be used to poll the BM-AV3 for alarms.

Set up switches (0x83)

This command will operate only when the video select switch on the unit front panel is in the remote position. It does, however, set up the BM-AV3 internal remote commands even when the unit is not in remote mode. Selecting the remote setting on the video select switch will activate these commands.

Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0

Byte 0

Ms bit of

Video select

Ms bit of Audio select

Audio select

Byte 1

Colour

bar enable

Ms bit of Right speaker select

Right speaker select

Ms bit of Left speaker select

Left speaker select

Byte 2

Ms Red

zone

Red zone Red zone Red zone Red zone

Byte 3

Ms

amber zone

Amber zone

Byte 4

AES

offset

Ms Peak type

Peak type

Ms bar type

Bar type Bar type

Audio select codes

Code Function 000

Analog audio input selected

001

AES audio input selected

010

SDI audio group 1 selected

011

SDI audio group 2 selected

100

SDI audio group 3 selected

101

SDI audio group 4 selected

111

Audio follows video selection

BEL DIGITAL AUDIO BM-AV3S BM-AV3 serial protocol

Video select codes

Code Function 00

Composite video input selected

01

SDI 1 input video selected

10

SDI 2 input video selected

11

Remote position of switch

Left and right speaker select codes

Code Function 00

Select audio input 1

01

Select audio input 2

10

Select audio input 3

11

Select audio input 4

Colour bar generator

Setting this bit will replace the current SDI image with colour bars.

Red zone data

The numerical value of the five bits of the red zone data corresponds to the length of the red zone. The origin of the red zone if the top of the bar graph.

Amber zone data

The numerical value of the five bits of the red zone data corresponds to the length of the amber zone. This zone is ‘attached’ to the bottom of the red zone.

Bar type

These 3 bits select the bar ballistics and type.

Code Bar type 000

AES

001

DIN

010

VU

011

BBC

100

Extended VU

101

Nordic

BEL DIGITAL AUDIO BM-AV3S BM-AV3 serial protocol

Bar peak indicator

These two bits select the peak indicator timing.

Code Time 00

No peak indicator

01

3 Second hold time

10

7 Second hold time

11

Indefinite hold time

AES offset

This bit selects the bar graph offset when AES is input to an analog bar graph.

Code Function 0

-18 dB

1

-20 dB

Set up alarms (0x84)

Bit 6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 Byte 0

Reset Auto Video Audio

Channel 4

Audio Channel 3

Audio Channel 2

Audio Channel 1

Byte 1

Toggle Disable

Anti- Phase 3/4

Anti-Phase 1/2

Over-level 4

Over-level 3 Over-level 2 Over-level

1

The Auto bit will cause the BM-AV3 to generate spontaneous ACK signals every second while an alarm is active. The toggle disable bit will inhibit the set-up function of the front panel toggle switch.

BEL DIGITAL AUDIO BM-AV3S BM-AV3 serial protocol

Request Detail (0x85)

This command will cause the BM-AV3 to respond with a frame containing the command 0XC5 and data describing the state of the unit and any alarms.

Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Byte 0

Ms bit of

Video select

Ms bit of Audio select

Audio select

Byte 1 Alarms

Video Audio loss

4

Audio loss 3 Audio loss 2 Audio loss

1

Byte 2 Alarms

Anti-phase

3/4

Anti-phase 1/2

Audio overlevel 1

Byte 3

Ms bit of Video Standard code

Video Standard code

AES 2 lock AES 1 lock SDI lock

Byte 4

Embedded

4

Embedded 3 Embedded 2 Embedded

1

Byte 5

Armed

Video

Armed Audio loss 4

Armed Audio loss 3

Armed Audio loss 2

Armed Audio loss 1

Byte 6

Armed Anti-

phase 3/4

Armed Antiphase 1/2

Armed Audio overlevel 4

Armed Audio overlevel 3

Armed Audio overlevel 2

Armed Audio overlevel 1

Request Current switch settings (0X86)

This command will cause the BM-AV3 to respond with a frame containing the command 0XC6, data describing the settings of the front panel and internal switches.

The data will be returned in the same format as the set up switch command. (0X85) The remote state is indicated by the value 3 for the video switch.

ACK format

ACK is a standard frame with command 0xC0 and one data byte. This byte contains brief alarm and status information.

Byte 0

SDI lock

AES2 lock

AES1 lock

Remote mode Auto Video Alarm Audio Alarm

NACK format

A reply indicating that an error occurred communicating with the MM2 it carries the command 0xC1. Brief error information is carried in two data bytes.

Byte 0

Error message value

Byte 1

Erroneous checksum character

BEL DIGITAL AUDIO BM-AV3S BM-AV3 serial protocol

Error message values

Value Message 1

A time out occurred after receipt of a valid start character

2

A character was detected before receipt of a start character.

3

A checksum error occurred. The erroneous value is placed in Byte 1

RS232 format

8 data bits, no parity, 2 stop bits, 9600 Baud.

BEL DIGITAL AUDIO BM-AV3S Problem solving

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The front panel provides five status LEDs.

The BM-AV3S status LEDs

The status LEDs have the following functions:

• ON – lights green when the unit is powered and switched on

• LIMIT – lights red to indicate that the soft limiter is protecting the speakers

• AES A/B – lights yellow to indicate presence of the AES A and/or AES B inputs

• SD – lights yellow to indicate presence of selected SDI input

BEL DIGITAL AUDIO BM-AV3S Problem solving

Sample problems and their solutions

There is no power to the unit

Check the power cabling and the integral fuse in the IEC mains socket at the rear of the frame. Check that the power switch at the rear is in the on position.

The display is too bright or too dim

Adjust the TFT brightness and or contrast with the on screen display.

The display colour saturation is incorrect

Adjust the TFT colour with the on screen display.

The display colours or hue are incorrect (NTSC only)

Adjust the display tint or hue with the on screen display.

The bargraph display does not have the desired ballistics or colour transition points

Check that the appropriate scale and colour transition points have been selected with the internal DIL switches.

Check that the chosen ballistics setting and bargraph scale graticules match.

Note:

In the unlikely event that the unit ‘locks up’ switch the unit off at the rear for a few seconds and then restore power.

BEL DIGITAL AUDIO BM-AV3S Specifications

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Audio inputs

Analog inputs impedance

25k Ω differential

Digital inputs impedance

110 Ω differential (XLR connector) or 75 Ω unbalanced (BNC connector)

Analog monitor outputs

Max output level

Noise +THD

+15 dB

-95 dB (Analog input)

-98 dB (AES input)

Frequency response

All analog outputs 20 Hz to 20 kHz ±1 dB

Main drive amp

Noise +THD -80 dB w.r.t. maximum output

Speaker driver units

Peak acoustic level (@2ft)

Shielding

100 dB SPL

Magnetic

Meters

Level meters 4 x hi-resolution tri-colour bargraphs

(All audio measurements made using Audio Precision un-wtd 22 Hz to 22 kHz

BEL DIGITAL AUDIO BM-AV3S Specifications

Video

Input 2 x SDI SMPTE 259M

1 x composite analog 1V p/p

Output

1 x composite video converted from selected SDI input on BNC connector

Screen TFT, 7 inch diagonal, 800H x 480V resolution

Controls Tint, colour, brightness and picture (contrast)

Scales and Ballistics

NORDIC: Overall dynamic range: 54 dB (+12 to -42 dB)

Attack time: 5 ms Fallback: 1.7 Sec per 20 dB decay

DIN PPM: Overall dynamic range: 55 dB (+5 to -50 dB)

Attack time: 10 ms Fallback: 1.5 Sec per 20 dB decay

BBC PPM: Overall dynamic range: (+12 to -12 dB from mark 7 to mark 1)

Attack time: 10 ms Fallback: 2.85 Sec (from mark 7 to mark 1)

VU: Overall dynamic range: 23 dB (+3 to -20 dB)

Attack time: 300 ms Fallback: 300 ms

VU EXT: Overall dynamic range: 80 dB (+20 to -60 dB)

Attack time: 300 ms Fallback: 300 ms

AES/EBU: Overall dynamic range: 60 dB (0 to -60 dB)

Attack time: 1 ms Fallback: 1.5 Sec per 20 dB decay

BEL DIGITAL AUDIO BM-AV3S Specifications

Housing

19” Rack Mount: 3U high. Outline Dimensions: 483mm(W) x 256mm(D) x 133mm(H) Outline Dimensions: 19inch(W) x 10inch(D) x 4.75inch(H)

Power

100W (max) 90-264 VAC 50-60 Hz Autoselect, Fuse 4A HAC

Environmental

Temperature 0 °C to 30 °C Humidity 70% max (non-condensing)

Weight

9 kg (20lbs)

Computer interface

9 pin RS-232 male PC-AT serial interface (null-modem)

bel Digital Audio BM-AV3S User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual