【 Weak current College 】 5 lines meeting the advantages and disadvantages of the system

Internet developments enable understanding of the network is becoming more and more deeply, more and more widely. At present all kinds of electronic products in the world are seeking an information. Then the product will have to use couldn't connect mode in the computer network is widely applied in five categories. In the AV network cabling, it seems to have gradually become a trend. We can see that a variety of audio and video products in this development. From intelligent projector to digital conference system, the central control system, matrix and switch, with five types of cable network as its new product development. Resulting in a series of questions in the discussion between distributors and friends. Here, our Conference system, for example, to look at a few questions: 1, all-digital conference system may not be used to connect to a distinction between? cat 5 cable connection is all-digital system? original professional cable connection is analog system? 2, 5 line advantages? 3 years has been used professional cable is thus marketed? first, no matter whether a cat 5 cable connection cable attached to the original with professional, are just a kind of connection. Both are able to transmit digital signals. Therefore, we cannot be used to determine the connection type is digital conference system or simulation conference system. 5 cable connection methods are widely used for criticism has its advantages. Five categories of line, also known as twisted pair, is now the most common transfer media, which consists of two mutually insulated copper wire, typical diameter of 1 mm. Two wires twisted together to prevent its electromagnetic induction in the adjacent line of interference in the signal. Existing twisted-pair cable in General consists of 4 twisted pairs. Twisted-pair can do plus metal mesh wire set of shield and divided enclosureed twisted pair (STP) and unshielded twisted pair (UTP). General computer local networks is using unshielded twisted pair (UTP). If the data volume, the best use of shielded twisted pair (STP). Network General cat 5 cable connector to an RJ-45 Crystal head; maximum effective transmission distance is the distance from hub 100m. If you want to increase the transmission distance between the two twisted-pair can install repeaters, up to four repeaters installed. As the installation of four relays connected five segments, the maximum transmission distance of up to 500m. Five types of line frequency bandwidth 100MHz. Frequency bandwidth (MHz) and cable the transferred data transfer rate (Mbps) is differentiated. Mbps measured unit time line transmission of binary digit number, measured in MHz is the unit of time line signal oscillation frequency. Twisted-pair up to CMSA/CD based (Carrier Sense Multiple Access/Collision Detection, carrier sense multiple access/collision detection) technology, namely 10BASE-T (10Mbps) and 100BASE-T (100Mbps) Ethernet network (Ethernet). Five types of line to now have not been all of the Conference system manufacturers (including some international brands), and its application to some deficiencies. We all know, in computer Ethernet current transmission is very faint, most of the data flow. According to IEEE802.3af, through Ethernet transmission power, transmission to each node's power is limited to 350 Ma. The current market conference systems are passive, power supply and data transmission in a transmission in the cable. While the Conference system power generally 100W-200W, supply voltage for 24V-48V. Then transfer current about 2A-8A. Far greater than the IEEE802.3af. So, this is a security risk. In particular, RJ45 Crystal head as a five-line connector, contact between them is very weak, large current can easily cause damage to the joints. On the connection, you need to focus on is the strong reliability a connecting line. RJ45 Crystal head and Conference unit connected to the RJ45 module interface connection simply rely on RJ45 port with the little card PIN. Using computer networks were very clear that the connection is very unstable, but in a computer network, a little bit of loose or temporary shedding innocent. But in meeting system cannot be accepted, in "hand"-style microphone unit connected, this loose and peeling leads from loose or shedding cells after all. Vote system is more serious, more needs to be strong, safe and reliable. Based on the above two deficiencies, so that part of the Conference system manufacturers still use a dedicated cable. In cable prices and use the extensive, dedicated cable behind five types of lines, but dedicated cable is all manufacturers follow standard still in use at all levels is, of course, has its good side. If the Philips "6P dedicated cable", Taiwan's "8PIN dedicated cable", Bella's "8PIN dedicated cable." The transfer rate and transmission frequency, the dedicated cable is not less than five lines. In all the special shielding the cable shield are added, no non-shielded cables. This special cable, the transmission power absolute security on safe, reliable, tested, and even resistance moment 10A of strong current. In the cable connections in all major manufacturers have adopted a professional card to their cable connection to enhance the security, stability, reliable work on all done. So, five categories of lines and dedicated cable in meeting system application is still in the field have advantages. We cannot be arbitrary five categories by a line judging the session connected to advanced system.