RTS APPLICATION NOTE 1:
RTS: Interfacing Two-Wire Partyline to Your Matrix
Two-wire partyline is a simple and cost-effective way of providing communications to a number of users who can share one or two channels. As the name implies, this kind of system ties everyone together with a single cable. The cable goes into a beltpack, which also has a jack for a headset. Each beltpack has a cable to the next beltpack in the chain.
In a single-channel system, everyone speaks and listens to everyone. In a two-channel system, it is possible to create two separate groups. Two-wire partyline actually uses three wires. The wire carries audio, supply voltage, and ground. In a two-channel system, the wire carrying the supply voltage also has a signal superimposed. This signal scheme is usually referred to as ground-referenced. Systems with so-called differential signaling require additional wires but we will not get into that here.
Num sistema single-channel, todos os utilizadores podem falar e ouvir-se entre si. Já num sistema two-channel é possível criar dois grupos separados. O sistema Partyline de 2-fios usa 3 cabos: o cabo que transporta áudio, a corrente de alimentação e a ligação “terra”. Num sistema two-channel, o cabo que fornece a alimentação também tem um sinal super-imposto. Este tipo de sistemas é geralmente referido como “ground-referenced”.
This Application Note shows you the many ways you can take advantage of your RTS matriz to link 2-wire analog equipment.
STAND-ALONE VS MATRIXED OPERATION
A two-wire partyline system can be used with nothing except a power supply and multiple beltpacks. This is the stand-alone mode of operation. In many cases, it is convenient to connect a partyline to a matrix. That mode of operation provides additional possibilities but in most cases it requires an interface between the two-wire system and the matrix.
User Case A: Stand-Alone
This is the simplest case, as discussed above. It requires nothing except beltpacks and a power supply. The example uses a PS-20 which is specific to the ground-referenced scheme from RTS.
User Case B: Stand-Alone integration with ODIN
A robust digital matrix in a compact 1RU space, built in OMNEO technology, eedundant power supplies, and energy-efficient design, uses less than 50W of power.
USE CASES C and D: Integration with ADAM / ADAM-M
ADAM and ADAM-M are modular systems with cards that provide different capabilities. The AIO-16A card is used for connecting analog keypanels. Because the audio uses four electrical wires (plus two for keypanel data), this format is sometimes called four-wire. Two-wire and four-wire cannot be inter-connected without an adapter.
RTS has two, the SSA-324 (an analog device) and the DSI-2008 (which has digital signal processing). Figure 3 and Figure 4 show the back of these two converters.
USE CASE E: Integration via OMNEO
It is possible to go directly from a two-wire partyline to high-quality audio over IP. Dante is supported by the OMNEO Matrix Interface (OMI), a card that goes into both ADAM and ADAM-M. Converters are available from several third-party suppliers. This example uses the M45DR from Studio Technologies. Figure 5 shows the back of that device.
The M45DR communicates via the RJ45 connector on the rear. In most cases, it would be connected to an Ethernet switch, which in turn is connected to the OMI-card. Dante eliminates the problem of creating unique analog cables, to connect from one device to another, as would be required in use cases C and D.
Conclusion: Two-wire partyline systems can be used in a stand-alone or matrixed configuration. The use cases are summarized in the table below:
RTS APPLICATION NOTE 2:
RVON - RTS Voice Over Network
RVON is a way of getting audio across long distance, without the need for dedicated infrastructure. RVON encodes the audio to allow it to be sent over the Internet. To use RVON, a matrix card is required, as well as a device on the other end, capable of sending and receiving RVON audio. This is shown in Figure 1.
With the exception of one single keypanel, the KP-3016A, all keypanels in the KP-Series family are capable of running RVON. The firmware for RVON may be downloaded for free from the RTS website.
Using the RVON-I/O
For analog products that need to be connected remotely, there is a converter called RVON-I/O. Using
the RVON-I/O, it is possible to connect analog products as well as legacy products, as shown in Figure 2.
Figure 2 shows RVON being used to connect an IFB, a KP-Series keypanel connected via AIO, a
legacy keypanel (KP-96/7) and a Zeus III with an analog keypanel.
There is also a software product, the Virtual Keypanel or VKP, running on a PC, which gives it the ability to transmit and receive RVON audio. Note the Cronus, ADAM, and ADAM-M all have the ability to use RVON, whereas Zeus III does not.
RVON in trunking application
One of the most commonly used applications for RVON is Trunking. An example is shown in Figure 3. Three intercoms are interconnected over RVON. The Trunkmaster issues commands to the controllers in each of the matrices to close crosspoints, meaning set up paths for audio. It is very important to understand the Trunkmaster does not actually switch any audio.
RVON for reduced BITRATE
RVON is not one single codec, it is three. The RVON hardware from RTS supports three codecs, G.711, G.729, and G.723 – all with different technical characteristics and levels of compression, as summarized in Table 1.
RVON Products
RTS has multiple RVON products to support the use of RVON in virtually any application:
- Matrix cards for Cronus, ADAM, and ADAM-M
- Firmware for KP-Series of keypanels (firmware may be downloaded for free)
- Software for ODIN
- Option cards for KP-32, RP-1000, KP 12 CLD, and DKP 16 CLD
- Software for PC (Virtual Keypanel)
- RVON-I/O converter for analog
Finally, a couple of technical points:
- RVON requires fixed IP-addresses to work. The network cannot support Network Address Translation (NAT). In networks that do support NAT, there are still solutions for making RVON work, but they may require additional hardware devices (to create VPN tunnels).
- The RVON firmware for KP-Series keypanels may be downloaded for free. To install it, an RTS supplied software program called Firmware Upload Tool (FWUT) must be used. FWUT is included with the OMNEO Suite, which may also be downloaded from the RTS website.
For more information about the RTS solutions we have to offer you, get in touch with our team!