Features & Configuration: RS-232, IR & Relay Control

Features & Configuration: RS-232, IR & Relay Control

RS-232 Serial Control

RS-232 is the most common control protocol for professional AV devices — displays, projectors, matrix switchers, audio DSPs, and amplifiers all typically expose an RS-232 port for control.

Port Configuration

Each RS-232 port must be configured to match the controlled device’s serial settings:

  • Baud rate: 2400, 4800, 9600, 19200, 38400, 57600, or 115200
  • Data bits: 7 or 8
  • Parity: None, Even, or Odd
  • Stop bits: 1 or 2
  • Flow control: None or Hardware (RTS/CTS)

Most AV devices use 9600 or 115200 baud, 8N1, no flow control. Always verify in the controlled device’s manual.

Cable Type

  • DB9 straight-through: Used when the device is wired as DTE (most AV devices).
  • DB9 null modem: Used when connecting two DTE devices. TX and RX are crossed.
  • KanexPro processors use a standard 3-wire RS-232 connection: TX, RX, GND.

Bidirectional Feedback

RS-232 ports support both sending commands and receiving feedback. Configure the port to listen for response strings and use them to update panel button states or trigger conditional logic in the script.

IR (Infrared) Control

IR control is used for devices that lack RS-232 or IP control — consumer displays, cable boxes, Blu-ray players.

IR Emitters

Connect a 3.5mm mono IR emitter cable to the IR output port. Place the emitter bud directly over the device’s IR receiver window. Most KanexPro processors support multiple independent IR emitter outputs.

IR Code Formats

  • Built-in library: Pre-loaded codes for thousands of devices. Select the brand and model in the GUI.
  • IR learning: Use the processor’s IR input port to learn codes directly from the original remote control.
  • Pronto hex: Import standard Pronto hex format IR codes from third-party databases.

IR Frequency

Standard IR carrier frequency is 38kHz. Some devices use 36kHz, 40kHz, or 56kHz. The processor auto-detects frequency when learning codes.

Relay Control

Relay outputs are dry contacts — no voltage is provided by the processor. They switch an external circuit open or closed.

Wiring

  • Normally Open (NO): Circuit is open at rest; closes when relay activates.
  • Normally Closed (NC): Circuit is closed at rest; opens when relay activates.
  • Maximum ratings: typically 1A @ 30VDC. Check the product manual for exact specs.

Common Applications

  • Projector screen up/down control
  • Room divider / motorized shade control
  • Power switching via external relay module
  • Door lock / door strike control
  • Lighting scene triggers (via lighting controller relay input)

Relay Commands

SET RELAY port1 CLOSE    # Close the relay
DELAY 500                # Hold for 500ms
SET RELAY port1 OPEN     # Open the relay

Digital I/O (CR-HOST8R Only)

Digital I/O ports can be configured as inputs or outputs. As inputs, they detect contact closures (door sensor, motion detector, button). As outputs, they provide a logic-level signal to trigger external devices.

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