This article describes one method of creating a system mute state using the GPI terminals on select Bose Professional processors.

Relevant Product(s)

• ControlSpace ESP-00
• ControlSpace ESP-00 II
• ControlSpace ESP-1240
• ControlSpace ESP-1240A
• ControlSpace ESP-1240AD
• ControlSpace ESP-1600
• ControlSpace ESP-4120
• ControlSpace ESP-88
• ControlSpace ESP-880
• ControlSpace ESP-880A
• ControlSpace ESP-880AD
• ControlSpace EX-1280
• ControlSpace EX-1280C
• ControlSpace EX-440C
• ControlSpace Designer

Procedure

It may be required by local fire codes for an audio system to automatically mute when a fire alarm is triggered. Using Bose Professional ESP and EX processors, this is easily accomplished. Consider the very simple configuration file seen below. The configuration file is attached to this article (see the side bar for Related Attachments).

The goal is to have the system audio mute when a fire alarm is active, and then automatically unmute when the alarm state has cleared. This functionality will require the use of a Normally Open (NO) or Normally Closed (NC) dry contact from the building's fire panel. This contact is wired to the CONTROL INPUT block on the rear panel of the processor. For the purposes of this article, it's assumed that input 1 is being used for the fire alarm panel contact. Wire NO or NC to the input 1 position, and COM to the ground position on the CONTROL INPUT block.

NOTE: It is generally considered best practice to use a Normally Closed contact for a fire alarm mute application. This means that the audio system will be active ("normal") so long as there is a connection between input 1 and ground on the control input block. In this scenario, if the wire connecting the fire panel to the processor is cut, removed, or otherwise compromised, the system will fail "safe" and audio will mute, indicating an issue that needs to be resolved.

In ControlSpace Designer, two parameter sets will be created, one for the muted state, and one for the unmuted state.

If there are user controls present in the system architecture (i.e. ControlSpace CC-16 or ControlSpace CC-64), it is preferable to apply the mute state to a block that is not being adjusted by a user control.

Since user controls typically interact with gain blocks for level adjustment and mute, the Analog Output - Amp block will be the stage where the mute is applied. To save the muted state of this block, double-click on the block to open its control dialog. Then click MUTE on each channel, turning the button red.

Click and drag the Analog Output - Amp block to the ParameterSets window, and drop it on the text of Param. Set 1: "Fire Alarm ACTIVE." If the output block contains more than one channel, a window will appear to select the desired output channel to be affected by this parameter set.

In this example, all Zones must mute, and both checkboxes are marked. Click Assign to create the Parameter Set. The parameters of both channels of the Analog Output - Amp block are saved in the Parameter Set.

To save the unmuted state, click MUTE again on each channel of the Analog Output - Amp block, returning the button to its normal grey color. Repeat the drag and drop process, this time dropping onto the second Parameter Set. The functionality of the Parameter Sets can be tested by clicking the orange Recall buttons. The MUTE button will activate and deactivate as each Parameter Set is recalled.

Double-click the GP In block to open its control dialog, and apply a meaningful label to the first input field.

Click and drag the text Param. Set 1: "Fire Alarm ACTIVE" and drop it on the the text Digital Control Input 1. A window will appear to select the state that activates the Parameter Set.

"ON" means the input is shorted to ground (closed), and "OFF" means there is no short to ground (open).

• If the fire panel is using a normally closed contact, then the "normal" (unmuted) state will occur when there is a short from the input to ground ("ON").
• If the fire panel is using a normally open contact, then the normal, unmuted state will occur when there is no short to ground ("OFF").

To select the mode for the "Fire Alarm ACTIVE" parameter set, select ON or OFF based on the type of dry contact used. In this example, the fire panel is using a NC contact, so "OFF" is selected.

Click and drag the second Parameter Set to Digital Control Input 1, and select the opposite state from the previous selection.

The functionality is tested by clicking ON or OFF to the right of the input text field.

NOTE: If a normally closed contact is used, in this scenario, the outputs will be muted upon pushing this configuration file to the processor unless there is a short from input 1 to ground. Ensure the fire alarm panel is properly wired to the control inputs in order for audio to pass.

Attachments

The file attached to this article is created in ControlSpace Designer v5.9.2 (see the side bar, Fire Alarm Mute.csp)