What Is The Difference Between RS232 And RS485 Chips?

RS232  and RS485  are common serial communication interface standards. They have obvious differences in electrical characteristics, communication methods, transmission distance, application scenarios, etc.Here is a comparison for you:

1. Electrical characteristics

RS232

• Single-ended signal (ground reference)
• Logic 1≈−3V−15V, logic 0≈+3V+15V
• easily disturbed

RS485

• Differential signal (symmetrical transmission between A/B lines)
• A−B differential voltage >+200mV means 1, <−200mV means 0
• Strong anti-interference ability

2. Communication method

RS232

• Point-to-point communication (1 to 1)
• Does not support multi-machine mounting

RS485

• Support multi-point bus (theoretically up to 32 transceivers, expandable to hundreds).
• Commonly used in industrial buses with one master and multiple slaves.

3.Transmission distance & rate

RS232

• The maximum distance is about 15m (up to tens of meters at low speed)
• Typical rate: tens of kbps

RS485

• The maximum distance is about 1200m (at 100kbps)
• Maximum speed up to 10Mbps (short distance)

4. Interface and wiring

RS232

• Commonly used DB9/DB25 interface
• At least 3 wires (TX, RX, GND)

RS485

• Commonly used terminal blocks or RJ45
• 2 wires (half duplex) or 4 wires (full duplex)

5. Application scenarios

RS232

• Computer serial ports, modems, old-fashioned instruments and equipment
• Suitable for short distance, point-to-point transmission

RS485

• Industrial automation, PLC, instrumentation, building control, security monitoring
• Suitable for long-distance and multi-point communication

Summary and comparison