How to use RS232, RS422 and RS485 interfaces to expand the network?

Engineers often find themselves with insufficient cable length to connect end devices with RS232, RS422 and RS485 interfaces to their computers or controllers. How to solve this problem? There are many ways to expand the RS232, RS422 and RS485 interface to solve this problem.

Before we begin, let’s review the maximum distance over which data can be transmitted based on the interface.

● RS232: up to 15 meters, point-to-point operation mode

● RS422和RS485-最长1200米，点对点或多播模式将RS232转换为RS422或RS485 ● RS422 and RS485 – up to 1200 meters, point-to-point or multicast mode converts RS232 to RS422 or RS485 ● RS422 and RS485 – up to 1200 meters, point-to-point or multicast mode converts RS232 to RS422 or RS485 ● RS422 and RS485 – up to 1200 meters, point-to-point or multicast mode converts RS232 to RS422 or RS485

The easiest way to extend the RS232 interface is to use

Convert RS232 to RS485 conversion cable

This increases the distance from a maximum of 15 meters to a maximum of 1200 meters.

Although the RS422 and RS485 interfaces are very similar, the RS485 interface is more common. Let’s take RS485 as an example.

通过中继器扩展RS485网络Expand RS485 network via repeater Expand RS485 network via repeater Expand RS485 network via repeater

If you are only a few hundred meters away, you can still extend the RS485 interface. For example, use the serial port server as a relay.

Expand RS485 network via optical fiber

What should I do if I want to extend the RS485 network to 2 kilometers or more?

Serial interfaces can be converted to fiber optics via optical converters.

Extend RS485 network via Ethernet

What if scaling over fiber is laborious, but you have a local Ethernet or Internet network?

You can use a serial interface server or a converter from RS232, RS422 and RS485 interfaces to Ethernet.

Extend RS-485 network via Wi-Fi

The RS485 interface can be connected to the Wi-Fi network through the wifi serial port server.

Expand RS485 network via radio channel

If Ethernet/Internet is not an option, consider a wireless channel solution.

Extend RS485 network via cellular modem

If the devices you want to connect are spread out over vast and difficult terrain, you can use a 4G cellular connection.

Keywords: Analog input and output module