Redback® A 1741B Message Player
Operating Manual
A 1741B
Message Player
The A 1741B is an MP3 based message player and tone generator designed for public address, security, customer direction
or emergency evacuation announcements.
1.0 INSTALLATION
Power requirements: The A 1741B requires a minimum of 12VDC at 300mA to work correctly with a maximum work-
ing voltage of 30VDC. Do not exceed 30VDC as it will cause permanent damage to the unit. A good working voltage is
between 12VDC and 24VDC. The power is connected via the 2.1mm (tip positive) DC socket on the rear of the unit (see
fig 1).
Output: Output is via the stereo RCA connectors on the rear. Output level is nominal 500mV but is related to the recorded
level of the MP3.
Input triggers: The input triggers are activated by closing contacts on the rear of the unit whether by a normally open
switch or a timer or controller. (Note: These triggers have a common ground).
Trigger Switches: The messages can also be activated by pressing the switches on the front of the unit. Note: The Alert
and Evac buttons must be held down for 3 seconds before they activate. This reduces the chance of accidental triggering.
Switched output: The switched output terminal is triggered when any zone is activated. The voltage is the same as the
power supplied to the unit. ie if the A 1741B is powered by 12V, the switched output voltage will be 12V.
2.0 PLAY MODES
Alternate: When the A 1741B is in Alternate mode (DIP1 switch1 OFF) (see Fig 3) the closing contact must be held for the
duration of the MP3 play time, if it is released before the MP3 ends the MP3 will stop playing immediately. If the contact is
held closed continually the MP3 will continue to loop over and over until the contact is released.
Momentary: In Momentary mode (DIP1 switch1 ON) (see Fig 3) a momentary closing contact or pulse on the trigger pins
will activate the MP3. The A 1741B will continue to play the MP3 till it finishes and will stop playing and wait for another
trigger activation.
To stop an MP3 playing when in Momentary mode the Cancel trigger or Cancel switch is used. A momentary closing
contact on the Cancel trigger or closure of the Cancel switch will stop the MP3 playing (it is recommended that the Cancel
contact or switch be held up to 2 seconds to ensure the MP3 stops playing)
User manual revision number 1.0 26/11/2019
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