EST3 Installation and Service Manual

System overview

Network Data Riser

Network Audio Riser

Equipment Enclosure

Central

Processor

Module

Local Rail Bus

Backup

Amplifier

Zoned

Amplifier

Zoned

Amplifier

Zoned

Amplifier

Zoned

Amplifier

Page Page EVAC Alert

Figure 1-5: Single amplifier failure

The amplifier failure caused the backup amplifier to automatically connect to the same audio source as the failed amplifier. The output of the backup amplifier replaced the output of the failed amplifier.

Note:

The backup amplifier will not replace an amplifier that has detected a field wiring problem to prevent the amplifier from driving into a shorted circuit.

3-ASU Audio Source Unit

The 3-ASU is the source of the network audio riser. Available audio sources are local and remote voice PAGE functions and the firefighter telephone PAGE function. An integral tone generator database is provided for the EVAC, ALERT and other functions. Alternately, the 3-ASU’s integral digital voice message playback unit can simultaneously provide up to 8 different prerecorded audio messages that may be assigned to any channel.

The multiplexer within the 3-ASU converts and compresses the real-time audio signal and converts it to a digital format. The output of the digital message playback unit and the integral tone generator database is already in the digital format. The 8 signal sources in digital format are then combined together as selected by the system designer using a multiplexer. This makes up the network audio riser signal.

EST3 Installation and Service Manual 1.9

System overview

Local mic.

Remote mic.

Firefighter’s telephone

Auxiliary input

Audio signals

Multiplexer

Network audio riser (eight digitized audio channels)

Digital message playback unit

Figure 1-6: ASU Signal Flow

Tone / message database

Digital signals

The amplifiers at the remote-panels extract the audio signals from the network riser, amplify it and send it to the speakers.

Local tone generator

Network audio riser

(eight digitized audio channels)

Network data riser

(command and control)

Demultiplex and decode

Figure 1-7: Amplifier Signal Flow

Channel selection and supervision

Power amp

25/70 VRMS supervised audio circuit

EOLR

Audio signal priority

During system configuration, each of the eight available audio channels is assigned one of the five available attributes listed in

Table 1-1. The Page, and Auxiliary attributes may only be assigned to a single channel. The General attribute may be assigned to up to four channels.

Table 1-1: Network audio channel parameters

Channel attribute Priority

PAGE 1

EVAC 2

ALERT 3

AUXILIARY 4

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System overview

Table 1-1: Network audio channel parameters

Channel attribute Priority

GENERAL 5

Each channel attribute has a priority level associated with it.

When more than one channel is commanded to source a given amplifier, the amplifier will connect to the source having the highest priority. The Page channel will only go active when the microphone push-to-talk switch is pressed.

Special audio source unit page modes

The front panel of the ASU offers four special page mode switches:

• EVAC

• Alert

• All Call Minus

These switches provide instantaneous switching of the page signal to the most frequently contacted areas of the building. The special page modes do not require any source switching by the zoned audio amplifiers. When a special page mode switch is activated, the signal content of the eight outgoing audio channels is modified. Figure 1-8 illustrates this principle.

In the normal page mode, the eight audio signal sources are each connected to a separate audio channel, as represented by a „ at the intersection of the signal source and the audio channel, shown at the lower left of Figure 1-8. Each audio channel is represented as a vertical line in this figure. The eight audio channels are actually multiplexed together and distributed over a common pair of wires called the network audio riser. The figure shows the system in the normal page mode, with the zoned audio amplifiers processing EVAC signals on the 1st and 3rd levels, a page signal on the 2nd level, and the alert signal on the 4th level.

EST3 Installation and Service Manual 1.11

System overview

Eight multiplexed audio channels on a two-wire circuit

Local tone generator

Power amp

25/70 VRMS supervised audio circuit

EOLR

ALERT

Local tone generator

Power amp

Local tone generator

Power amp

25/70 VRMS supervised audio circuit

EOLR

EVAC

25/70 VRMS supervised audio circuit

EOLR

PAGE

25/70 VRMS supervised audio circuit

Local tone generator

Power amp

EVAC

Network audio signals

Page

Evac

Alert

Auxiliary

General1

General2

General3

General4

= Audio source unit audio signal to audio channel connection

Normal mode

Audio signal distribution during special paging modes

Page

Evac

Alert

Auxiliary

General1

General2

General3

General4

ALL CALL mode

Page

Evac

Alert

Auxiliary

General1

General2

General3

General4

Page to EVAC mode

Page

Evac

Alert

Auxiliary

General1

General2

General3

General4

Page to ALERT mode

Figure 1-8: Audio Source Unit Special Page Mode Signal Flow

EOLR

Page

Evac

Alert

Auxiliary

General1

General2

General3

General4

ALL CALL MINUS mode

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System overview

The All Call mode is used to send a page to the entire facility.

When the All Call switch is activated, the Audio Source Unit is put into the all call mode. In this mode, the zoned audio amplifiers do not all transfer to the page channel. Rather, the

Audio Source Unit redirects the page signal source to all the audio channels. Figure 1-8 shows the all call page source to audio channel connections in the lower left corner. Note that all channels receive the same signal. Any amplifier on the system, regardless of the audio channel selected, will receive the page.

Any amplifiers that were previously idle will power up and receive the page.

The Page to EVAC mode is used to send a page to the areas automatically receiving the evacuation signal. Activating the

EVAC switch causes the Audio Source Unit to enter the page to

EVAC mode. In this mode, the zoned audio amplifiers connected to the EVAC channel do not transfer to the page channel. Rather, the Audio Source Unit redirects the page signal source to the

EVAC channel. Figure 1-8 shows the page to EVAC mode page source to EVAC channel connections. The page and EVAC audio channels both receive the page signal. Any amplifier connected to either the page or EVAC audio channels will receive the page. The alert, auxiliary and general channels are connected to their respective signal sources, as in the normal mode.

The Page to Alert mode is used to send a page to the areas automatically receiving the alert signal. Activating the Alert switch causes the Audio Source Unit to enter the page to alert mode. In this mode, the zoned audio amplifiers connected to the alert channel do not transfer to the page channel. Rather, the

Audio Source Unit redirects the page signal source to the alert channel. Figure 1-8 shows the page to alert mode page source to alert channel connections. The page and alert audio channels both receive the page signal. Any amplifier connected to either the page or alert audio channels will receive the page. Any amplifiers that were previously idle will power up and receive the page. The EVAC, auxiliary and general channels are connected to their respective signal sources, as in the normal mode.

The All Call Minus mode is used to send a page to all areas NOT automatically receiving the EVAC or alert signals. In high rise applications, all call minus is an effective way to quickly select stairwells. Activating the All Call Minus switch causes the

Audio Source Unit to enter the all call minus mode. In this mode, the zoned audio amplifiers connected to the auxiliary and general channels do not transfer to the page channel. Rather, the Audio

Source Unit redirects the page signal source to the auxiliary and four general channels. Figure 1-8 shows the all call minus mode page source to auxiliary and general channel connections. The

EST3 Installation and Service Manual 1.13

System overview page, auxiliary and four general audio channels all receive the page signal. Any amplifier connected to the page, auxiliary or general audio channels will receive the page. The EVAC and alert channels are connected to their respective signal sources, as in the normal mode.

Automatic messaging

One of the features of the 3-ASU Audio Source Unit is the method used to monitor the integrity of the digital audio system.

When an audio messaging system is configured, default audio messages are recorded for the Evacuation and Alert channels.

The text of default messages should be generic in nature, and should not include location-specific instructions. When the system is in the normal condition, the 3-ASU continuously transmits default messages over the network audio riser. The zone amplifiers use the default messages to verify their operational integrity, as well as the integrity of the riser wiring.

When an alarm is detected, the evacuation and alert message channels are selected by the amplifiers in the appropriate areas in the facility, as directed by the system rules. If a specific evacuation message has been programmed to play in response to the alarm, it is sent out over the evacuation channel. Location specific evacuation messages contain information and instructions that should only be used for a specific alarm location. Should a second alarm from another location be received, the evacuation message playing as a result of the first alarm may not be appropriate for the second alarm.

Note:

In the event of conflicting messaging instructions caused by multiple alarm events, the system will play the default evacuation message, whenever two or more different messages are requested at the same time on the evacuation channel.

Automatic message processing is illustrated in Figure 1-9. By reverting back to the generic default evacuation message in multiple alarm location scenarios, no one can be misdirected by the wrong message. Default messages also play during alarms when no location specific message has been requested.

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