RS-485 Converter - A flexible multi-point networks standards

For many people today term "network" is more than just connect their wireless access point and to ensure that the office can access the Internet, and perhaps files on other computers at home o. The conditions of RS232, RS422 or RS485 little to say today's consumers who are used to USB Plug and Play, and perhaps an Ethernet cable for connection to a reliable high-speed router. However, allowing the world to the mass market consumer electronics, and RS-485 is astandard network important for industrial applications and techniques, such as device control, data acquisition, remote device management and so on. So let's re RS-485, what is and what it can do.

First, unlike the standard RS232, RS485 is not possible, a protocol or data-out pin. Instead, it describes the electrical characteristics of drivers and receivers in digital systems.

Like the RS-422 ports, RS-485 systems use "balanced" signalspositive and negative voltages (in the range of -6 to +6 V) on twisted pair cables. This makes them much more immune to interference as "deranged" RS232 signals and also allows speeds of up to 10 Mbps over short distances is a maximum connection distance of 4,000 meters at low speed.

However, while RS-422 is limited to a single driver, with up to ten knots or receiver, RS-485 is a true multi-point with a maximum of 32 drivers and 32 receivers. This means thatthat up to 32 riders can communicate through the same pair of wires. What if 32 is not sufficient for a question? Then, a repeater allows you to add a further 32nd If this is not enough, additional repeater has up to the guideline system, which is usually 256 units.

As far as connections go, the RS-485 standard is not set, a certain kind of result you can use standard DB25 or DB9 serial ports, but also to RJ11 or RJ45, a terminal strip,or a variety of DIN connectors. Connect to any computer via standard RS232 port requires an interface card or RS485 or RS232 to RS485 converter. In commercial and industrial classes are of high quality. When an impulse, ground loops and transient pulses are a problem, look for a drive opto-isolated to protect your computer.

Note that the network configuration or 485-2-wire or 4 wire. drivers are 2-wire system and receivers connected on a singlea pair (plus a special signal ground). The nodes can communicate, but communication is only half-duplex. In a 4-wire (plus ground), a driver for all channels of the node is connected to a pair of receivers and transmitters of the nodes are connected to the receiver on a second driver torque. This allows full duplex communication, but also the central nodes can not communicate directly. Each system has its benefits and uses.

Since485 or, as they are called correctly, EIA-485 signals are not limited to a certain standard, can be used in a wide range of control and automation. Add the minimum wiring and high resistance to electromagnetic interference and you have a standard that could be important in coming years.