DPM 2500 P – Digital Audio Management Unit

The Digital Audio Management Unit DPM-2500 P is a digital signaling audio control unit used to initiate/manage live paging, audio signal routing and playing pre-recorded audio messages. The unit is ideal for different audio applications including the background music and professional public address. It is equipped with an internal monitoring of all alarm-relevant parts, internal error logging and permanent monitoring of all system buses In general, the unit is equipped with 8 independent (DSP based) audio input channels. On the output side, you can use 8 independent preamplifier outputs. The digital Audio management unit is used in combination with DAA amplifiers.

Up to ten digital selective remote microphone units DPM-2550 A or DPM-2550 B can be operated with each DPM unit. If a DAM-2550 A system call station is to be connected to the audio management unit, this can be done over TCP/IP media or remote microphone port.

The audio signal processing allows simultaneous operation of 8 independent speech paths (8×8) matrix in connection with a supplementary software license. With the digital-analog input module, up to 8 monitored digital or analog inputs are available. In order to play a selected input channel with priority, the NF-Digital-1-Channel-Priority-Control-Module is used. Furthermore, an NF-Digital External Volume Control Module allows remote volume control of a selected input channel. On the input side, there are high-performance audio AD converters with 128x oversampling and input channel gain adjustable in 6 dB steps (0 – 42 dB) and on the output side with high-performance audio DA converter with 128x oversampling and switchable output channel gain (0/6 dB) is available. For a professional, unadulterated reproduction of speech and music, each input/output features five bands parametric equalizer. Each audio input could be configured as Line or Mic input supporting Phantom power or VOX input type.

The digital signal processor (DSP part) supports a sampling frequency of 48 kHz. The current device configuration (commissioning presets) and the factory settings (delivery status) are stored in a non-volatile memory (EEPROM). The Digital Audio Management Control has integrated 32- bit ARM Cortex M3 digital processor (120 MHz) that offers sufficient computing power for real- time control of all processes. The unit is equipped with 4GB Inbuilt message storage ( 48 KHz /16 bits)

The digital control of all operating functions is carried out by 2 function keys, a rotary encoder, as well as through 8 additional, freely assignable rotary encoders (or alternatively with an optional RS-232 Interface Module). The graphic LCD display with 32 x 120 pixels and 16-bit 20MHz slave controller control allows plain text display and the display of pictograms. The software license enables operation with a display in the respective national language. The special software license includes all user-specific factory programming of the system, e.g. the times for the start of periodically repeated announcements or going signals, as well as the group definitions for an alarm or a call announcement.

The automatically changing background color of the display is used to visualize error states. The color of the backlighting of the display is switched depending on the activated operating mode. The colour assignments are as follows:

1) Gray color : Snooze mode is active
2) Blue color: Normal Operation
3) Yellow color: Fault status
4) Red color: Emergency status is active
5) Purple color: Service status is active

The watchdog-monitored alarm output (2-pole potential-free changeover contact) deliver a defined error status even if the processor fails.
The DPM- 2500 P unit can be equipped with two optional digital interface module for networking:

1) DMS-2034 A: Digital Media Network Module (Dante)
2) DMS-2036 A: Digital Ethernet Network Module

The audio sampling rate over the Ethernet media is 48 KHz with bit depth of 24 bits. Each unit can transmit up to four simultaneous audio channels on the TCP/IP network.