Installation and Setup: RTMS Echo Sensor

Serial Communications Using Sx-300 Protocol

A serial connection to the Echo sensor can be made using the Sx-300 protocol and a serial terminal server. The terminal server converts the Sx-300 protocol from TCP to serial. NOTES:
  • Sx-300 protocol data can only be collected via Ethernet or serial, not both concurrently
  • If Ethernet TCP is required concurrently, an Ethernet switch must be used.
  • Before connecting the terminal server to the data collection device to the following:
  • Confirm the pinout of the terminal server and the required serial protocol (RS-232, RS-485 4-wire, RS-485 2-wire).
  • Confirm the pinout of the serial endpoint.
  • Verify the pins are appropriately mapped to ensure communications.
Figure 1: Serial Communications Hardware Connections
See Table 1 for wiring instructions for the serial cable between the terminal server and endpoint.
TCP to:
From Serial Terminal Server
To Serial Endpoint
RS-422/RS-485 4-Wire
RX- RX+ TX- TX+ GND
TX- TX+ RX- RX+ GND
RS-485 2-Wire
RX/TX+ RX/TX- GND
RX/TX+ RX/TX- GND
RS-232
RX TX RTS* CTS* GND
TX RX CTS* RTS* GND
NOTE: RTS and CTS are optional. Besides the hardware connections, both the terminal server and the Echo sensor must be configured. Configure the Serial Terminal Server
  • Change the default IP address to work with your desired network (a static IP address) is recommended). Most applications require the IP address to be on the same subnet as the Echo sensor; however, it may not be required depending on how verbose the network is.
  • This is the IP address that will be used in the Echo set up.
  • Set the local port for the Endpoint configuration. This is the port that will be used in the Echo set up.
  • Set the desired serial settings based on the application (defaults should be sufficient for most applications).
  • Protocol (RS232, RS485 (4-wire), RS485 (2-wire)
  • Baud rate
  • Baud rate
  • Data bits
  • Parity
  • Stop bits
Configure the Echo Sensor In the Legacy protocols section of the Settings page, Sx-300 protocol must be selected and the IP address and port number from the terminal server configuration must be entered for the Serial server field. For complete information, see Legacy protocols: Sx-300 Protocol.
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