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Choosing the Right Wireless Intercom System: 2-wire & 4-wire Interfacing (Part 2 of 9)


When trying to decide what Clear-Com wireless is right for you, 2-wire and 4-wire interfacing may be an essential need. Here, we discuss this section of the Choosing the Right Wireless Infographic and why either of these interfacing capabilities is important. 

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Why is interfacing, in general, so important? It's one thing to have a stand-alone system. It doesn't need to communicate to anything else, no other technologies need to be included. It operates by itself. But what if you have a facility wired system your productions have outgrown the existing intercom? You and your staff need to discuss the workflow needs and the decision to expand is adding a wireless partyline intercom system. NOW interfacing becomes important and understanding those methods come first.There are two common techniques that make interfacing a wireless base intercom system possible: it's called 2-wire and 4-wire.

2-WIRE: a communications system where the path is the same for both talk and listen. In intercom channels, there are two wires (one path). 2-wire systems can be 2-wire balanced or 2-wire unbalanced. Example: analog partyline is a 2-wire system.

4-WIRE: a communications system where the path is different for talk and listen. In intercom channels, there are four wires (two paths). 4-wire systems can be 4-wire balanced or 4-wire unbalanced. The 4-wire circuit gets its name from the fact that a balanced pair of conductors was used in each of two directions for full-duplex operation. Example: digital matrix, cameras, 3rd-party systems, etc. 

CLEAR-COM WIRELESS AND INTERFACINGStarting at an entry level, and within the most simplistic of group communications, you wouldn't need to interface to anything else, like a small group, in the same location, that only need to communicate among the crew. In this setting, a DX100 system would do the job. It does not support connections to any other external communication of audio devices. This compact and portable single-channel digital wireless intercom system  supports up to 15 beltpacks or all-in-one headsets per base station. DX100 employs Digital Frequency Hopping Spread Spectrum (FHSS) and is approved for worldwide 2.4 GHz license-free operation. The DX100 is the most economical wireless full-duplex partyline production intercom available anywhere. Most Clear-Com wireless base systems offer interconnectivity by providing a 2-wire or 4-wire interface or both. With all instances of external interfacing, it will always be on a per wireless channel basis.The DX300ES is a digital wireless communication system that enables hands-free full-duplex secure communication on two independent channels, or both channels at the same time. It can be operated with AC or battery power, like the DX100. Multiple base stations can be interconnected for expanded capabilities. In addition to the standard communication among base station and wireless beltpack operators, the system provides a 10-pin terminal strip connector for easy connection to 4-wire intercom systems. There is one analog 4-wire audio interface per channel with send and receive level trim controls to balance the audio. There are no 2-wire interfaces. To accommodate connecting analog 2-wire intercoms, it would be necessary to convert the 2-wire to 4-wire. Refer to a 2-wire to 4-wire external converter, such as a Clear-Com IF4W4, EF-701M or CCI-22.The following models provide analog 2-wire interfacing, as well as analog 4-wire. In all cases of 2-wire interconnectivity, provision to select between a Clear-Com or RTS compatible system is provided with a selector button or switch. When connecting external intercom 2-wire connections, a Clear-Com or RTS power supply is required. The DX210 and DX410 operate and perform with private, secure two-channel digital wireless intercom communication. The DX410 also features optional jumper settable 2-wire and 4-wire bridging circuitry. The bridging capability allows the option for combining the 2-wire and 4-wire ports together on either Channel A or B in such a way that the 2-wire and the 4-wire are capable of talk/listen capability along with the wireless users.The FreeSpeak II is Clear-Com's flagship wireless intercom system that can operate in 1.9 GHz, 2.4 GHz, or a mix of both on the same system. The base station offers 12 wireless partyline channels and 12 groups. The base includes four 2-wire analog partyline ports with call signal and four 4-wire audio ports with call signal. These 2-wire ports and 4-wire ports can then be configured to any or all of the 12 wireless channels or 12 groups. The base station can be used in main station mode with talk and call soft keys or as a headset station for communication and monitoring from the panel. The base station's digital displays allow easy system configuration directly from the base station or through the browser-based Core Configuration Manager (CCM) tool. The wireless beltpack features up to five communication routes per beltpack using four programmable pushbuttons, two rotary encoders and a reply button. All four 2-wire ports have software-enabled power function to supply 850mA DC on each pair of connectors for powering Clear-Com compatible or RTS analog wired devices.