is also fairly resistant to noise which is one more reason why it is favored in industrial environments. RS232 to RS485 converters are mostly used in industrial and commercial environments. The reason is that the RS485 converter can be used for multi-drop networks, meaning that you for example can connect multiple RS485 devices to one computer. Up to 32 devices can be connected in one network to communicate on a single pair of wires (plus a ground wire), and the number can even be increased by using RS485 repeaters. This type of communication is called half-duplex communication. Most quality RS485 converters can communicate in this manner of up to 4000 feet (1200 meters). The RS485 converter Okay, so how do you connect a RS232 to RS485 converter? The RS232 to RS485 converter can be used for point-to-point connections (connecting one RS232 to RS485 converter directly to another RS232 to RS485 converter) and point-to-multipoint networks (connecting one RS232 to RS485 converter to multiple RS232 to RS485 converters. The main differences between these RS232 to RS485 converter units are that some of them can have a DB9 connector whereas others have a terminal screw header or RJ11 connector, The serial RS232 to RS485 converter and RS232 to RS422 converter units, also called serial converters, are small electronic devices used to convert a serial RS232 signal, (for example the COM port in older computers) into either RS485 or RS422 signals. The typical serial converter does this in both directions which is also referred to as a bi-directional converter.

Examples of uses for a RS232 to RS485 converter could be for connecting cameras, scales, meters, scanners, PLC's or most other industrial equipment to a computer.The RS485 Master could be a computer and the slave could for example be a camera. As you can see the data lines A- and B+ are simply connected to the RS485 Slave's A- and B+ respectively. The converters will communicate with only A- and B+ connected, however it is very important to also connect the ground wire in the finished system to establish a steady reference point to prevent data loss and other bad things. We will here not go into the specifics of how the RS232 or RS485 protocol works, but if you are interested in this then there is lots of RS232 and RS485 information on Wikipedia, including how a USB to serial adapter works. We will however demonstrate the most common ways of connecting a RS232 to RS485 converter. The RS232 to RS485 itself, regardless of what model you choose, is simply a device which can convert standard RS232 data signals into RS485 signals and vice versa. Most RS232 to RS485 converters can convert data in both directions, from RS232 to RS485 and from RS485 to RS232, this is also called a bi-directional converter.

Many port-powered RS232 to RS485 converters provides an option for supplying external power. If in doubt, use an externally powered converter, then you are sure that it gets sufficient power. I using for example a USB to Serial adapter these same assumptions can be applied. The RS422 converter is used for data transmission, using balanced or differential signaling, it is mainly used in industrial and commercial environments since lots of process equipment and machinery have this protocol built-in. The RS232 - RS422 converter is also often used in older serial devices such as older PLC's and terminal equipment. The advantage of the RS485 protocol is that this it can transfer data over longer distances, up to 4000 feet, and have up to 32 nodes per single network, and it can be used for multi-point networks where multiple serial devices are setup in a bus network.What is called 'Automatic Send Data Control', which controls the data flow, is strongly recommended for most applications and devices, this feature is built into most modern RS232 to RS485 converters. dramatically increase power consumption so it should not be done, and is mostly not needed at shorter distances. Due to the increased power consumption termination is also rarely done when using port-powered converters. RS485, also known as TIA/EIA-485 is a standard serial communications protocol defining the electrical characteristics of a serial converter, drivers and receivers for use in balanced RS485 digital multipoint systems. Even RS485 is not commonly as popular as RS232 it is extremely useful for converters in industrial and commercial environments. A RS232 - RS485 converter is often used in industrial data acquisition and control applications where multiple serial devices communicate with each other through a converter. A RS232 - RS422 converter is a 4-wire, full-duplex, differential protocol with multi-drop capabilities and a recommended distance limit of 4000ft. ANSI/TIA/EIA-422-B is the American national standard for the RS422 protocol. When shopping for a RS232 to RS485 converter you should first determine if you need an industrial strength or a commercial/consumer grade converter, this depends on which environment you plan to use the converter. Next you should determine if you need and isolated or non-isolated converter, where after you can decide if you need an externally powered converter or if you can use a port-powered converter. Next you can find the connector type you need, either DB9 or DB25 connectors, terminal screw header, RJ11 connector or a combination hereof. Finally you should decide if you want LED lights for the TX/RX lines, this can be very helpful when troubleshooting.