RU-BNF Format-A Bi-Directional Network Interface The Format-A Bi-Directional Network Interface shall be an RDL RU-BNF. The unit shall provide a Dante compatible Ethernet interface plus one input and three outputs compatible with RDL Format-A endpoint devices. The unit shall convert four analog audio sources to a Dante-enabled network. Three converted channels shall originate from the Format-A input jack and the fourth channel shall be fed from an auxiliary input. The unit shall convert four networked Dante digital audio channels to analog audio. Three converted channels shall be distributed to the three Format-A output jacks and the fourth channel shall feed an auxiliary output. Each Format-A input and output jack shall provide dc power to connected Format-A senders and receivers from an external 24 Vdc power supply connected to the unit. The unit shall provide network connection through an RJ45 type shielded connector equipped with LEDs for Link and Speed. The Speed LED shall illuminate when the unit is connected to a Dante network with a transmission speed of 100 Mbps. The unit shall support a bit depth of 24 bits and sample rates of 44.1 kHz and 48 kHz. The unit shall convert between digital and analog formats at nominal standard professional levels of +4 dBu for a digital audio value of 18 dBFS. The unit shall, for each Format-A input pair, provide audio frequency response of 20 Hz to 20 kHz (± 0.5 dB) with total harmonic distortion of less than 0.1% and a noise floor exceeding 75 dB below the normal rated operating level of -18 dBFS, and a minimum of 18 dB of headroom above the normal rated operating level. Crosstalk between any pair shall exceed -80 dB from 20 Hz to 20 kHz. The unit shall provide an auxiliary line-level balanced audio input at a nominal rated input level of +4 dBu with an input impedance greater than 20 kOhms. A recessed, single-turn gain trimmer shall be provided in the front panel to produce normal operating level for an input range of -16 dBu to +12 dBu. The input shall not clip during application of an input signal up to +22 dBu. The auxiliary input shall be provided on a detachable terminal block. The auxiliary input shall provide audio frequency response of 20 Hz to 20 kHz (± 0.75 dB) with total harmonic distortion of less than 0.1% and a noise floor exceeding 75 dB below the normal rated output level of +4 dBu, and a minimum of 18 dB of headroom above the normal rated operating level of -18 dBFS. The unit shall provide a green LED signal presence indicator that varies in intensity as a visual indication of the relative audio level of each of the three Format-A input pairs. The indicator shall provide positive visual indication of signal presence for signals exceeding an amplitude 20 dB below a normal operating level of +4 dBu. The unit shall provide a dual-LED VU meter to indicate proper adjustment of the auxiliary input gain. The dual-LED meter shall be calibrated to normal operating level. A green LED shall display a correlated linear minimum to maximum intensity for signal levels from 15 dB below normal operating level to normal operating level. A red LED shall indicate signals exceeding normal operating level. The unit shall, for each Format-A output pair, provide audio frequency response of 20 Hz to 20 kHz (± 0.75 dB) with total harmonic distortion of less than 0.1% and a noise floor exceeding 85 dB below the normal rated output level of +4 dBu, and a minimum of 18 dB of headroom above the normal rated output level of +4 dBu. Crosstalk between any pair shall exceed -80 dB from 20 Hz to 20 kHz. During the absence of all digital audio inputs, the outputs shall fully mute with a residual noise at least 100 dB below the normal rated output level of +4 dBu. The unit shall provide an auxiliary line-level balanced audio output at a nominal rated output level of +4 dBu with an output impedance of 150 O. The output circuit shall be configured to produce an unbalanced output of proper phase between the positive output leg and ground. The auxiliary output shall be provided on a detachable terminal block. The auxiliary output shall provide audio frequency response of 20 Hz to 20 kHz (± 0.5 dB) with total harmonic distortion of less than 0.1% and a noise floor exceeding 75 dB below the normal rated output level of +4 dBu, and a minimum of 18 dB of headroom above the normal rated output level of +4 dBu. The unit shall provide a green LED signal presence indicator that varies in intensity as a visual indication of the relative audio level at each of the four channel outputs. The indicator shall provide positive visual indication of signal presence for signals exceeding an amplitude 20 dB below a normal operating level of +4 dBu. The front face of the unit shall provide graphical labels protected beneath a polycarbonate protective surface. The front face shall include LED indicators to indicate the presence of unit power, audio signals and Dante system and synchronization lock. The unit rear face shall provide LED indicators for the presence of dc power on each Format-A jack. In the event of a wiring fault that demands excessive current from any Format-A input or output jack, an automatically resetting fuse shall interrupt the power to the specific jack and the associated LED shall extinguish until the wiring fault is cleared. The unit shall measure 5.8" (15 cm) W; 1.7" (4.3 cm) H; 5.2" (13.2 cm) D and be compatible with RDL RACK-UP mounting accessories. The unit’s electrical chassis shall be fully constructed of metal, comprised of aluminum and steel members. The chassis shall include an integral provision for surface mounting. The unit shall be equipped to operate from a 24 Vdc ground-referenced power supply with a maximum current not exceeding 150 mA plus connected Format-A loads. The unit shall utilize an external power supply connected through one of two power inputs, one detachable terminal block or one dc jack. The unit shall be engineered, assembled and tested in the U.S.A. and be specified for continuous duty in professional installed systems. The unit shall be specified for operation in an ambient temperature between 0 and 40 degrees C. The unit shall comply with relevant EMC requirements and shall bear the CE marking. The unit shall be an RDL RU-BNF.