The unit's dual Gigabit Ethernet ("GigE") network interfaces support redundant Dante operation. And to meet the latest interoperability standard the Model 5422's Dante implementation meets the requirements of AES67. An integral web server allows fast and flexible configuration of the unit's networking, audio, and Dante performance. Front-panel indicators, an LCD display, and pushbutton switches provide personnel with direct access to key operating parameters. The Model 5422 can be powered by 100-240 V, 50/60 Hz mains or a source of 12 volts DC. The lightweight enclosure mounts in one space (1U) of a standard 19-inch rack.
Two versions of the Model 5422 are available. The Model 5422-01 provides one 32-channel audio engine. The Model 5422-02 provides two 32-channel audio engines for a total of 64 input and output channels. The size and scope of a specific application will dictate which Model 5422 version is applicable. The term "audio engine" was selected to describe a set of audio input, processing, routing, and output resources that can be configured to support specific intercom and talent-cuing functions. Unlike general-purpose Dante digital matrix devices, the Model 5422 is optimized to allow direct support for these special broadcast and general intercom applications.
Configuration choices select how each 32-channel audio engine is segmented, named, and then designated as to how the audio is processed.
The ability to segment a 32-channel audio engine into multiple groups allows efficient use of the Model 5422's Dante channels. As all Dante intercom beltpacks are essentially 4-wire devices (having independent receiver (input) and transmitter (output) channels) "virtual" (simulated) party-line functionality must be created within the Model 5422's audio engines. This requires that the maximum number of participants (users) on any one "party-line" be defined.
The 32 channels offered by an audio engine can be configured into what are called groups. Simple configuration choices in the Model 5422's menu pages allow the number of groups and their sizes to be selected. Groups can range in size from 32 channels (a complete audio engine being used for a single group) to having just four channels. The size of a group will dictate how many devices and associated users can be part of any one party-line or how many channels will be impacted by a processing setting for a specific group. Ten choices allow a wide range of group configurations to be selected. The default setting for each audio engine is to have four 8-channel groups. This leads to the Model 5422-01 having four 8-channel groups and the Model 5422-02 having eight 8-channel groups. Refer to the Specifications section for a detailed list of the group sizes that are available.
Each group can be assigned a unique name. These names would typically reflect how the specific groups are going to be utilized. Names such as Camera PL, Lighting Intercom, or Engineering would be typically used in broadcast-oriented intercom applications. The configured names are automatically used by the Model 5422's Dante Interface, providing clarity when routing Dante channels using applications such as Dante Controller. Each group name can be a combination of up to 28 alpha or numeric characters. Channel numbers are automatically appended to the entered names to provide identification of the specific channels within the Dante environment.
Group Operating Modes
While the primary application for the Model 5422 is to create party-line (PL) intercom circuits, each group can be independently configured from among four operating modes: party-line, IFB, summing bus, and pass-thru.
Party-Line: When a group is set for party-line operation the Model 5422's audio processing circuitry creates a series of unique "mix-minus" outputs, one for each channel in the group. These specialized outputs allow each intercom user assigned to that specific group (a "party-line") to hear all members of that group except for themselves. (Thus comes the term "mix-minus" or a mix of all source but themselves.) By each user receiving a mix-minus signal precise control of each user's sidetone audio level and overall audio quality can be maintained.
IFB: The IFB mode is specifically included for productions that utilize the Remote Integration (REMI) model where production personnel are located physically apart from on-air talent. "Interruptible foldback" (IFB) talent cue signals, each typically created from a program audio source and a voice-only interrupt source, are critical for supporting the needs of on-air personnel. Creating these in a REMI environment can be challenging. However, with the Model 5422 IFB becomes a simple matter. Each IFB function uses two Dante input channels (program audio and interrupt audio) and two Dante output channels (program with interrupt and program-only). Configuration choices allow the presence of interrupt audio to be recognized by voice-detect (VOX) or tone-detect (TOX) algorithms. Each will allow creation of excellent talent cueing "feeds." However, TOX provides a unique operating scenario where an 18 kHz (nominal) tone, combined with interrupt audio, can quickly and reliably activate and deactivate an IFB function. In this way an IFB-active signal provided by way of a proprietary data link isn't required for fully "pro" IFB signals to be created. During interrupt activity the program audio can be attenuated (or fully muted) following a configurable parameter. A Model 5422 can have as few as two independent IFB functions by selecting a 4-channel group. Selecting a 32-channel group can provide 16 independent IFB functions. As such, using a Model 5422-02 allows the creation of up to 32 independent IFB functions.
Summing Bus: When a group is configured for summing bus operation audio sources assigned to the group's input channels are mixed (combined) at unity (no gain added or subtracted). The resulting mix is sent to the first output channel associated with that group. No level control or input muting is provided. This mode can be useful for general-purpose audio mixing applications where multiple Dante channels need to be combined.
Pass-Thru: Each group can be independently selected to run in a special mode called pass-thru. This implements an audio function that routes each Dante input (receiver) channel directly to its associated Dante output (transmitter) channel. This simple but important function will allow any Dante signal to utilize the Model 5422's capability to support up to 32 Dante flows. This can be useful as a "flow expander" when used in an application that includes Dante-compatible products that utilize Audinate's Ultimo™ integrated circuit. (Many products from Studio Technologies use Ultimo.) While an excellent cost-effective means of implementing Dante, Ultimo has several limitations. The first is its ability to support only two transmitter and two receiver flows. Routing Dante signals through pass-thru channels on a Model 5422 group can facilitate integration with applications that require additional flows. The second limitation is that Ultmo does not provide AES67 support. By routing Ultimo transmitter channels through a Model 5422 group configured for pass-thru AES67 compliance can be achieved.
Channel Level Adjustment
The nominal level of each Dante input (receiver) channel and Dante output (transmitter) channel can be individually adjusted. This would apply to the 32 channels associated with the Model 5422-01 and the 64 channels with the Model 5422-02. The adjustment range is ±12 dB in 1-dB steps. This capability can be useful when using a Model 5422 to interface various pieces of equipment that may have different internal operating levels.
The Model 5422 supports 24-bit, 48 kHz sampling digital audio signals that interface using Dante. All audio processing within the Model 5422 is performed using high-speed 32-bit programmable logic. This ensures that the audio performance is excellent, providing the expected benefits of minimal distortion, low noise, high headroom, flat frequency response, and extremely low latency.
The Model 5422 is compatible with many Dante-compliant devices including intercom and listen-only beltpacks from Studio Technologies. These include the 2-channel Model 370A and Model 371A Intercom Beltpacks and the 4-channel Model 374A Intercom Beltpack. The Model 362 Listen-Only Beltpack supports broadcast IFB ("interruptible foldback") and general audio monitoring applications. The Model 5422 will function directly with these and other Dante-supporting devices such as matrix intercom systems, audio consoles, wireless intercom base stations, and commentator consoles.
Overall Networking Capability
Using the Dante Controller application program, the Model 5422's two Gigabit Ethernet ports can be selected to operate in one of three modes: switched, redundant or split. In the switched mode a single Ethernet connection can be used for Dante audio transport and to access the Model 5422's configuration web pages. The second Model 5422 Ethernet port can be used to interface with another piece of network equipment. In the redundant mode two independent Ethernet connections can be used to implement Dante's redundant network capability. In this mode the Model 5422's primary Ethernet port will provide access to the management web pages. In the split mode, called Pri Dante/Sec Mgmt, the Model 5422's primary Ethernet port will be used by the network associated with Dante while the secondary Ethernet port will be used to access the management web pages. This allows separate networks to be maintained for Dante and maintenance and configuration purposes.
The Model 5422 allows an AC mains source of 100-240 V, 50/60 Hz to be directly connected. It can also be DC powered using a 10-18 volt source that is connected via a broadcast-standard 4-pin XLR connector.
If both AC and DC power sources are connected to a Model 5422, the unit will be powered by the AC mains supply. Only if the AC mains source fails will a load be placed on the DC source. This allows a source of DC, typically a battery pack, to serve in a backup capacity. With this arrangement normal operation can continue even if AC mains power is lost.
Updating and Future Capabilities
Updating of the Model 5422's operating software can be easily performed using the unit's integrated FTP (file-transfer protocol) client. All program software files and configuration parameters are stored in non-volatile memory.
It's anticipated that additional capabilities will be added to the Model 5422. These may include auto-mix and audio gating functionality. Auto-mix resources would allow groups configured for party-line, IFB, and summing bus operation to offer increased audio intelligibility. The auto-mix performance should match that provided by any propriety hardware- or software-based products currently on the market. Audio gating would be applicable for the pass-thru mode, helping to reduce background noise associated with talent cue signals.