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Serial Service

DB9(RS-232/422/485)

  • Enable: Activate the serial interface for communication.

  • Standard: Select a specific protocol type for electrical signaling.

    • RS232 uses single-ended signaling (point-to-point, <15m).
    • RS422 employs differential signaling (1 driver → 10 receivers, 1200m).
    • RS485-4 supports 4-wire full-duplex with dedicated TX/RX pairs.
    • RS485-2 uses 2-wire half-duplex for multi-drop networks (32+ devices).

  • Mode: Select the mode accordingly.

    ① TCP Server is a passive endpoint that listens for incoming TCP connections.

    • Local Port: Enter the listening port (e.g., 5020) for accepting incoming TCP connections. Configurable, but avoid well-known ports like 80.
    • Timeout: Specify a duration in seconds (0-1000) before a connection is closed due to inactivity. 0 means no timeout.

    ② TCP Client initiates active TCP connections to servers.

    • Destination address: Enter a fixed target IP/domain (e.g., 192.168.1.100) for reliable endpoint connection.
    • Destination port: Enter a predefined service port requiring handshake.

    ③ UDP is a connectionless protocol for low-latency broadcast/multicast.

    • Local Port: Enter a dynamic/static port bound for sending/receiving datagrams (e.g., 1234 for sensor broadcasts).
    • Destination address (Optional): Enter a dynamic/broadcast IP (e.g., 255.255.255.255).
    • Destination port (Optional): Enter a flexible port binding without verification (e.g., 1234 for sensor broadcasts).

    ④ ModBus TCP is an industrial protocol (Layer 7) using TCP/IP for device control.

    • Local Port: Fixed to 502 by default for protocol compliance. Non-standard ports may break interoperability.
    • Max connections: Enter a number (1-128) to limit clients that can connect at the same time.
    • Timeout: Enter the maximum wait time for slave device responses.

  • Baud rate: Select to define the speed of data transmission for serial communication, measured in bits per second (bps).

  • Data bits: Select to define the number of bits (typically 5-8) used to represent each character in serial communication.
  • Stop bits: Specify how many stop bits are used to mark the end of each byte in serial communication.

  • Parity: Set how the system checks for errors in data transmission by adding an extra bit to each data frame.

    • None disables parity checking.
    • Even makes the total 1s count even (including parity bit).
    • Odd enables single-bit-error detection just like Even parity, but it demands an extra signal transition. Industrial systems often prefer Odd for better noise immunity.

  • Termination Resistor: Enable to activate the 120Ω termination resistor. Recommended for use at the bus end of RS422/RS485 to reduce signal reflections.

6PIN(RS-422/485)

  • Enable: Activate the serial interface for communication.

  • Standard: Select a specific protocol type for electrical signaling.

    • RS422: Differential signaling (1 driver → 10 receivers, up to 1200m).
    • RS485-4: 4-wire full-duplex with dedicated TX/RX pairs.
    • RS485-2: 2-wire half-duplex for multi-drop networks (32+ devices).

  • Mode: Select the mode accordingly.

    ① TCP Server is a passive endpoint that listens for incoming TCP connections.

    • Local Port: Enter the listening port (e.g., 5020) for accepting incoming TCP connections. Configurable, but avoid well-known ports like 80.
    • Timeout: Specify a duration in seconds (0-1000) before a connection is closed due to inactivity. 0 means no timeout.

    ② TCP Client initiates active TCP connections to servers.

    • Destination address: Enter a fixed target IP/domain (e.g., 192.168.1.100) for reliable endpoint connection.
    • Destination port: Enter a remote service port.

    ③ UDP is a connectionless protocol for low-latency broadcast/multicast.

    • Local Port: Enter a dynamic/static port bound for sending/receiving datagrams (e.g., 1234 for sensor broadcasts).
    • Destination address (Optional): Enter a dynamic/broadcast IP (e.g., 255.255.255.255).
    • Destination port (Optional): Enter a flexible port binding without verification (e.g., 1234 for sensor broadcasts).

    ④ ModBus TCP is an industrial protocol (Layer 7) using TCP/IP for device control.

    • Local Port: Enter a port fixed to 502 by default for protocol compliance.
    • Max connections: Enter a number (1-128) to limit clients that can connect at the same time.
    • Timeout: Enter the maximum wait time for slave device responses.

  • Baud rate: Select to define the speed of data transmission for serial communication, measured in bits per second (bps).

  • Data bits: Select to define the number of bits (typically 5-8) used to represent each character in serial communication.
  • Stop bits: Specify how many stop bits are used to mark the end of each byte in serial communication.

  • Parity: Set how the system checks for errors in data transmission by adding an extra bit to each data frame.

    • None disables parity checking.
    • Even makes the total 1s count even (including parity bit).
    • Odd enables single-bit-error detection just like Even parity, but it demands an extra signal transition. Industrial systems often prefer Odd for better noise immunity.

  • Termination Resistor: Enable to activate the 120Ω termination resistor. Recommended for use at the bus end of RS422/RS485 to reduce signal reflections.