Audio Switching Module 3

Emergency personnel, security staff or public utility workers: all of them are sometimes tasked with informing and warning the public. This can be required in a disaster situation, in traffic or in general deployment situations. Usually, the only way to do so is a public address microphone which is connected to the exterior loudspeakers of a tone sequence system.

If additional audio - or low-frequency - sources are to be imported, other media such as MP3 players or cellphones are usually at hand. For these devices the ASM 3 is the interface to the tone sequence or amplifier for public address.

The audio sources are selected via a CiA447-compatible control unit, routed to the amplifier’s audio frequency inputs from the ASM 3 and played through the pressure chamber loudspeakers. Additionally the ASM 3 offers the option of a 10-minute voice recording which can be played in a continuous loop or alternately with the tone sequence. The flexibility and quality of audio frequency signal processing are two more assets completing this product.



  • Switching between up to 4 audio frequency signal sources + 2 PTT
  • Source selection, recording / playing of public address and volume
    control via CAN447 control unit
  • Activation of audio frequency paths by line or via automatic gain



  • CAN447 component
  • Use with TFV 6x4 12 V / 24 V + 7x4 12 V / 24 V
  • Electrical connection available on the cable harness of the TFV 6x4, operation with HBE 300 (integrated microphone + push to talk) or BE 3xx + rod microphone)
  • Two mute outputs
  • Presetting the basic volume levels of the audio frequency sources on the unit



  • (1) Exterior loudspeaker. Here: 2x DKL 604
  • (2) CAN447 control unit. Here: HBE 300
  • (3) Audio frequency source. Here: TETRA digital radio communication unit (connection via internal radio communication
    unit loudspeaker)
  • (4) Audio frequency source. Here: USB/SD slot of the stereo system
  • (5) second microphone. Here: rod microphone
  • (6) Audio frequency source. Here: MP3 player
  • (7) CAN447 control unit. Here: BE 304
  • (8) Tone sequence amplifier TFV 6x4 / 7x4


Application options in the command vehicle pictured

From the driver’s cabin:


  • Command speaking
  • Recording voice announcements
  • Playing voice announcements
  • Playing voice announcements elternately with the tone sequence
  • Selecting audio frequency sources or control volume via HBE 300


  • A2: Selecting radio message of the radio transmitter (may require additional devices) and transmitting them to the outside
  • A3: Transmitting existing MP3 audio recordings to the outside


From the radio communication station:

  • A4: Command speaking
  • A5: Transmitting existing MP3 audio recordings to the outside
  • A6: Selecting audio frequency source or control volume via BE 304



  • F1: transmission to the outside by the amplifier 6*4 via the exterior loudspeaker(s) 604



product information

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