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Serial Port Settings

To configure the serial port settings of the device:

  • DTU
  • Serial Port Settings

Basic Settings​

The serial communication parameters of RLTK421 must match the RS485 serial device parameters. Otherwise, communication between devices will fail. Therefore, the baud rate, data bits, stop bits, and other serial communication parameters of the RS485 device must be the same as those of RLTK421. This is essential for reliable and accurate serial data transmission.

SerialSettings-421

ParameterDescriptionDefault Value
Baud rateSupports 1200 / 2400 / 4800 / 9600 / 19200 / 38400 / 57600 / 115200 / 230400115200
Data bits88
Stop bits1 / 21
ParityNONE / ODD / EVENNONE
Packaging interval (ms)10–6000010
Packaging length (byte)5–15001000

Operating Mechanism​

Time Triggering​

When receiving data via UART, RLTK421 continuously monitors the time interval between two consecutive bytes. If this interval is greater than or equal to the configured threshold, the system considers the frame complete.

Otherwise, data continues to be collected until the packet length reaches the configured byte threshold (default is 1000 bytes). The frame is then transmitted as a TCP or UDP packet to the network.

The timing threshold represents the inter-byte arrival time and can be configured between 10 ms and 60000 ms. The factory default is 10 ms.

This parameter can be configured using the AT command: AT+UARTFT=<time>.

UARTTiming1-421

Length Triggering​

While receiving UART data, the device continuously checks the number of received bytes. When the number of bytes reaches the configured threshold, the frame is considered complete and is transmitted as a TCP or UDP packet.

The packet length threshold can be configured between 5 and 1500 bytes, with a default value of 1000 bytes.

This parameter can be configured using the AT command: AT+UARTFL=<length>.

UARTTiming2-421