Why is RS485 better than RS232

The choice between RS485 and RS232 is often a crucial decision when it comes to establishing a reliable and stable communication network. While both are widely used for serial communication, there are several reasons why RS485 has gained popularity over its predecessor.

Higher Transmission Speeds

One significant advantage of RS485 over RS232 is its capability to achieve higher transmission speeds. RS485 supports data rates up to 10 Mbps, whereas RS232 is limited to only 115.2 kbps. This high-speed capability of RS485 makes it suitable for applications that require fast and efficient data transfer, such as industrial automation systems and networking environments.

Longer Communication Distance

An essential characteristic of RS485 is its ability to operate over longer distances compared to RS232. RS232 is typically limited to communication distances of only 15 meters due to its voltage levels and susceptibility to electrical noise. In contrast, RS485 can reach distances up to 1200 meters with the help of proper signal conditioning and balanced line drivers. This extended range makes RS485 ideal for applications spread across large areas or in harsh industrial environments.

Multi-Drop Capability

RS485 offers a unique feature called multi-drop capability, which allows multiple devices to be connected on the same bus. Unlike RS232, where communication is inherently point-to-point, RS485 enables communication between one driver and multiple receivers simultaneously. This makes RS485 a preferred choice when multiple devices need to communicate with a central controller, minimizing wiring complexity and reducing costs in complex systems.

Noisy Environment Resilience

In industrial settings, electrical noise is an inevitable challenge. RS485 is designed to handle noise and interference effectively, making it more immune to external disturbances. By using differential signaling and balanced line drivers, RS485 can reject common-mode noise, ensuring reliable communication even in noisy environments. This robustness makes RS485 the preferred choice for applications where electromagnetic interference (EMI) is a concern.

In conclusion, RS485 surpasses RS232 in terms of transmission speed, communication distance, multi-drop capability, and resistance to noisy environments. These advantages have made RS485 an increasingly popular choice in various industries where reliable and efficient serial communication is critical.