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In theatre and performance venues, RS-485 networks are used to control lighting and other systems using the DMX512 protocol. By using repeaters very large RS-485 networks can be formed. Because they are produced in such large quantities, Cat 5 cables are relatively inexpensive, often less than half the price of specialty RS-485 cabling. SENSEWAY connects to WIRED PROs using custom-sized RS485 cables and a T connector. Up to 10 WIRED PROs can be connected to SENSEWAY within a total range of 100m of RS485 cable. RS-485, like RS-422, can be made full-duplex by using four wires. This allows RS-485 to implement linear bus topologies using only two wires. RS-485 supports inexpensive local networks and multidrop communications links, using the same differential signaling over twisted pair as RS-422. Combined with the right cables, they are going to guarantee the creation of stable and functional RS485 networks. Digital communications networks implementing the standard can be used effectively over long distances and in electrically noisy environments. These distances I'm talking about are greater than 100 meters. 100 ohms, Cat 5 cables almost meets the electrical requirements for RS-485 cables. The capacitance is close to 12.5 pF/foot but there is a small impedance mismatch (100 ohms for Cat 5, 120 ohms for RS-485).

End of line termination resistor (120 ohm 1/4 watt) to be installed at both ends of network. The value of each termination resistor should be equal to the cable characteristic impedance (typically, 120 ohms for twisted pairs). Check out also our article about BIAS and TERMINATION resistors. Watch out for bargains. The EIA has officially disbanded and the standard is now maintained by the TIA as TIA-485, but engineers and applications guides continue to use the RS-485 designation. RS-485 is used as the physical layer underlying many standard and proprietary automation protocols used to implement industrial control systems, including the most common versions of Modbus and Profibus. For fixed laying Maximum shielding capacity in accordance with EMC requirements, Cable for Modbus bus systems, SUCOnet P, Modulink P, VariNet-P, Dry and damp environments, Suitable for various bus systems based on RS485 / RS422. Multiple receivers may be connected to such a network in a linear, multidrop bus. Because a mark (logic 1) condition is traditionally represented (e.g. in RS-232) with a negative voltage and space (logic 0) represented with a positive one, A may be considered the non-inverting signal and B as inverting. Circuits may be terminated on screw terminals, D-subminiature connectors, or other types of connectors.

PC environment. 8P8C modular connectors are used in this case. The termination also includes pull up and pull down resistors to establish fail-safe bias for each data wire for the case when the lines are not being driven by any device. Without termination resistors, signal reflections off the unterminated end of the cable can cause data corruption. Under some conditions it can be used up to data transmission speeds of 64 Mbit/s. 24 AWG solid wires, which are typically used in Cat 5 cables, can break easily when connected to a screw terminal block, which does not provide any strain relief. Our security solution products are based upon cutting edge technologies that are unique in the security industry. This cable is supplied in a 200 metre length on a timber drum and provides a one cable run solution to each access controlled door. No matter the devices, it is always good on real site installation to use a shielded cable, with 18-22AWG wiring and the shield connected ONLY to one end of the line. A good choice is to use a two pair, individually shielded, twisted pair cable such as Belden 3107A or equivalent or Belden's 3106A that has an extra ground conductor wire.

Rs485 is low impedance balanced , so twisting the pair helps with noise immunity as well as reducing the attenuation effect of higher baud rates due to the parallel capacitance of the wires in the cable jacket over the long lengths. The shield works as a "drain" for any noise that could be picked up by the RS485 network and "drain" it to ground. This way, the lines will be biased to known voltages and nodes will not interpret the noise from undriven lines as actual data; without biasing resistors, the data lines float in such a way that electrical noise sensitivity is greatest when all device stations are silent or unpowered. When When you try our products you will experience the difference that these technologies provide! What you see in our website is not just another version of video security products produced from old technologies. Our Security Solutions was created to provide commercial security products from latest technologies.