Industrial RS232 to RS422/485 Adapter / Serial Converter, 15kV ESD Protection CS-428/9AT-PRO2

  • Sale
  • Regular price $51.00

The SystemBase CS-428/9AT-PRO2 converts RS232 signals to RS422 or RS485. It is a fast and efficient solution to overcome the distance limitations of RS232 or for connecting to industrial devices with an RS422 or RS485 interface with 15kV ESD protection.

No additional software is required for operation. With an easily accessible DIP switch, you can configure the interface for RS422 or RS485. The CS-428/9AT-PRO2 is fully compatible with the serial COM port on your PC.


  • Maximum Communication Speed: 921.6Kbps
  • Industrial Grade Temperature: -40~85°C (IEC 60068-2-30/33)
  • RS422/RS485 side: absorb 400W surge from a waveform of 10/1000μs peak pulse
  • ESD Protection 15kV (IEC 61000-4-2: ESD level 4 protection)
  • External power not required (When DTR signal line is enabled)
  • Hardware-based Auto Toggling
  • RS422/RS485 mode selectable by an external switch
  • Max. 10 Devices Connectable for RS422 Multi-Drop Mode
  • Max. 10 Devices Connectable for RS485 Mode
  • Power: 9~12V, 500mA

Auto RTS Control (Auto Toggling)

The CS-428/9AT-PRO2 has a built-in hardware feature that performs automatic toggling to prevent devices from sending data simultaneously. This operation is crucial when multiple devices are connected to prevent electrical collisions that lead to errors and unstable communications.

What is RS485 Echo Mode?

Different from RS485 Non-echo mode, RS485 Echo Mode enables the output signal line to function as the input signal. Therefore, it is not necessary to read the echoed data to confirm whether the data sent crashes with data sent by another device. With the CS-428/9AT-PRO2, all operations are controlled by the hardware so no additional modifications are required to the application program.

CS-428/9AT-PRO2 Specifications:


  • Maximum Speed: 921.6 Kbps
  • Maximum Distance: 1.2 Km. 24AWG twisted pair cable
  • Connectors:
    • RS232: DE-09S (DB9 Female)
    • RS422/RS485: Terminal Block 5 Pins
  • Signal Lines:
    • RS232: TXD, RXD, RTS, DTR, GND
    • RS422: TXD+, TXD-, RXD+, RXD-
    • RS485: TRXD+, TRXD-
  • RS422 Mode: Point to Point, Multi-Drop
  • RS485 Mode: Echo, Non-Echo
  • Slide Switch: RS422/RS485 selectable


  • Dimensions (W x L x H): 37 x 74 x 19 mm (1.45 x 2.92 x 0.75 inches)
  • Weight: 33g / 1.16oz

Operating Environment

  • Operating Temperature: -40~+85 C
  • Storing Temperature: -40~+85 C
  • Humidity: 5~95% Non-Condensing


  • Certificates: CE, KC

Package Includes:

1X CS-428/9AT-PRO2 Industrial RS232 to RS422/485 Adapter / Serial Converter,
Download Guide, Warranty Policy

Additional Resources:

CS-428/9AT-PRO2 Manual, Utilities and Specifications Downloads (SystemBase Website)