RS232 Relay Board

RS232 Relay Board at a Glance...

  • 8 Relays Installed on a Circuit Board
      - ProXR Lite: Non-expandable
      - ProXR: Expandable up to 256 relays
  • RS232 Interface with Choice of Connector
      - Onboard DB-9 connector
      - Screw terminal serial connection
      - Off-board DB-9 cable option
      - Connects to any standard COM port
  • Industry Leading ProXR Command Set
      - Program in almost any language
      - Send precise commands to control relays
      - Control individual, grouped, or all relays
      - Toggle, flash, and timing commands
  • ProXR AD8 Command Set
      - Read 0-5V sensor inputs
      - Monitor external sensors or contact closures
      - Relay Activator: inputs can directly control relays

Selecting the Proper Amperage

For more information on selecting a board with the correct relay amperage for your application see Choosing a Proper Amperage.

Looking for an 8-channel RS-232 relay board? Choose from expandable ProXR models, non-expandable ProXR Lite versions, and DPDT relay options for advanced switching needs.

RS-232 Relay Controller Boards

RS-232 Relay Controllers allow you to control relays using a standard DB-9 serial connection. These boards use onboard firmware to control individual relays, relay banks, or all relays at once using simple serial commands with automatic status refreshing.

RS-232 Relays connect directly to computers and third-party control systems through any available COM port at standard baud rates, making them easy to integrate into automation software, data collection systems, and industrial control environments.

These controllers are ideal for applications that require reliable, wired communication with a single control device.

Choosing Your 8-Channel RS-232 Relay

8-channel RS-232 relay boards are available in ProXR Lite and ProXR versions:
  • ProXR Lite - Non-expandable, streamlined design
  • ProXR - Expandable up to 256 relays
Both versions use the same firmware and support the full ProXR Command Set, giving you identical control capabilities. The difference is expandability.

Select Your Relay Type & Amperage

RS232 Relay BoardChoose the 8-channel RS-232 relay controller that matches your load requirements:
  • SPDT Relays: 5A, 10A, or 20A
  • SPST Relays: 30A
  • DPDT Relays: 1A, 3A, or 5A (ProXR only)
Need help selecting the right relay amperage?
Use our Choosing a Proper Amperage to make the right call for your application.
ProXR Lite vs ProXR
  • ProXR Lite: Non-expandable, streamlined design for fixed-size projects
  • ProXR: Expandable up to 256 relays for growing systems
  • Both: Same firmware, same ProXR Command Set, same control features
💡 Relay Pros Pro Tip:
If you think your project might grow, choose the ProXR version. You'll start with 8 relays today and expand up to 256 later - without replacing your controller.