DB9 Male Header RS232 & RS485 Converter Board

Specifications:

1. Interface:

• RS232: DB9 Male connector
• RS485: Terminal block (typically 2-wire A and B lines for half-duplex communication)

2. Communication Protocol:

• RS232 to RS485 conversion: Converts standard RS232 signals to RS485.
• Half-duplex: RS485 is typically half-duplex, meaning data can flow in one direction at a time.

3. Data Rates:

• RS232: Up to 115200 bps (can vary depending on the device)
• RS485: Supports baud rates from 300 bps to 115200 bps, depending on the application.

4. Operating Modes:

• Automatic Direction Control (for RS485): Automatically controls the direction of data flow without the need for external control signals (like RTS) for half-duplex operation.

5. Power Supply:

• Can be powered through:
  • External DC Supply: 5V or 12V depending on the design.
  • Power through the RS232 port: Some designs can draw power directly from the RS232 port (check compatibility).
• Current Consumption: Typically less than 50 mA.

6. Pinout (DB9 Male Connector RS232 side):

• Pin 2: RXD (Receive Data)
• Pin 3: TXD (Transmit Data)
• Pin 5: GND (Signal Ground)
• Pin 7: RTS (Request to Send) – optional for some designs
• Pin 8: CTS (Clear to Send) – optional for some designs

7. Pinout (RS485 side):

• A: RS485 Data A (Differential +)
• B: RS485 Data B (Differential -)
• GND: Ground (optional, depending on the system)

8. Isolation:

• Optical Isolation (optional): Some converters use optical isolation to protect the RS232/RS485 circuits from electrical surges, grounding issues, or other electrical noise common in industrial settings.

9. Surge Protection:

• Surge protection and ESD protection are often integrated to handle high-voltage transients on the RS485 side.
• TVS Diodes: Protection for ESD (Electrostatic Discharge) and surge protection.

10. Distance:

• RS485 Communication Distance: Up to 1200 meters (4000 feet) at lower baud rates (e.g., 9600 bps). Higher baud rates decrease the maximum distance.
• RS232 Communication Distance: Typically up to 15 meters (50 feet).

11. Termination Resistor:

• RS485 networks often require a termination resistor at each end of the communication line to minimize signal reflections. Some boards include a built-in resistor that can be enabled/disabled via a jumper.

12. Temperature Range:

• Operating Temperature: -40°C to +85°C
• Storage Temperature: -55°C to +125°C

13. Compatibility:

• Compatible with a wide range of RS232 and RS485 devices such as microcontrollers, PLCs, PCs, and industrial machines.

14. PCB Layout:

• Compact PCB design with mounting holes for easy integration into industrial systems.
• Dimensions: Typically small form factor (e.g., 50mm x 40mm, but varies by model).

15. LED Indicators:

• Power LED: Indicates power to the board.
• TX/RX LEDs: Shows data transmission and reception status on the RS485 bus.

16. Mounting Options:

• Through-hole or header pins for easy mounting on development boards or enclosures.

17. Applications:

• Industrial automation
• Data acquisition systems
• SCADA (Supervisory Control and Data Acquisition)
• HVAC control systems
• Remote device monitoring