4.2.4 RS-232 / UART

Configuration

This configuration area is used to set up serial communication on the SmartSampler2.
It defines how the device exchanges data with connected sensors or modules through the selected port.

• The configuration options are the same for all serial ports (RS-232, UART1, UART2).
• Each port must be configured individually if it is in use.
• Once configured, the SmartSampler2 will handle all serial communication according to the specified settings (baud rate, data format, delimiters, etc.)

Serial Configuration

• Baudrate
  • Select the communication speed (bits per second).
  • Must match the baud rate of the connected device (e.g., 9600, 19200, 115200).
• Configuration
  • Defines the serial frame format: data bits, parity, stop bits (e.g., 8N1 = 8 data bits, no parity, 1 stop bit).
  • Ensure this setting matches the external sensor/device.
• Save
  • Stores the selected settings permanently in EEPROM.

Delimiter / Values to Save

• Delimiter
  • Defines how incoming data is split into values (e.g., comma, semicolon, tab).
  • Choose the same delimiter used by the connected sensor output.
• Values to save
  • Enter the number of values from the incoming data stream that should be stored.
• Start position
  • Index of the first value to save (starting from the left).
• Every value
  • This setting tells the SmartSampler which elements from a delimited string should be extracted and stored.
    
  • Some sensors output alternating variable names and values, while others provide only data values.
    • Example 1 – Variable + Value pairs
      Device output: Variable1,value1,Variable2,value2,Variable3,value3,…
      Desired: only extract the numeric values.
      → Set Every Nth Value = 2 (store every second element).
      
    • Example 2 – Data only
      Device output: value1,value2,value3,value4,…
      Desired: store all values.
      → Set Every Nth Value = 1 (store every element).
  • This way, the SmartSampler can flexibly adapt to both “header+value” and “value-only” device formats.
• Save
  • Stores delimiter and value extraction settings.

Variable Mapping & Commands

This section defines how the SmartSampler should interpret sensor output and which commands it should send to control the sensor.

• Variable Header
  • Enter the variable names in the order they appear in the received data string.
  • Example: “pH,pH_mV,temp”
    If the device sends 6.5, -12, 21.3, the SmartSampler will map them as:
    • pH = 6.5
    • pH_mV = -12
    • temp = 21.3
  • Tipp: Use unique variable names for all your variables to prefent mixing them up
• Data Command
  • Command string the SmartSampler2 sends to the sensor to request updated measurements.
  • Example: “Data”
• Clean Command
  • Command string the SmartSampler sends to trigger cleaning or wiping if supported.
  • Example: “Wipe”
• Exclude
  • Defines text patterns to ignore in incoming data lines.
  • Useful for filtering out unwanted startup messages or headers.
  • Example: “Header:pH,pH in mV,Temperature”
    → SmartSampler will skip lines containing this header, ensuring only valid readings are stored.
• Save
  • Stores the configuration.
• Load
  • Reloads previously saved configuration.

Notes & Best Practices

• After saving, test the connection via the Live Monitor to confirm valid data reception.
• Always confirm baud rate and serial format from the sensor’s datasheet.
• Use a delimiter that matches the actual sensor output string.
• Keep variable mapping & commands as specific as possible to prevent saving unwanted lines.

Test

The Test tab allows you to validate the serial communication setup for RS-232 and UART ports. It is divided into two areas: Data and Debug.

Data Area

• Displays the variables defined in the Configuration tab (Variable Header).
• Shows the position, variable name, and the latest value received from the sensor.
• Updates live whenever data is received and parsed according to the configured delimiter and Every Nth Value setting.
• Useful for verifying that the variable mapping matches the actual sensor output.

Example:
If the Variable Header is defined as:

 pH,pH_mV,temp

and the sensor sends:

6.7,-15,21.3

the Data area will display:

• Pos 1: pH = 6.7
• Pos 2: pH_mV = -15
• Pos 3: temp = 21.3

Debug Area

• Provides tools to send manual commands and view raw sensor responses.

Functions:

• Manual commands:
  • Enter any command string expected by the sensor (e.g., Data, Wipe).
  • Press Send to transmit it via the selected port.
  • The raw response will appear in the Response window.
• Cont. read:
  • When enabled, the SmartSampler:
    1. Applies the current Configuration settings (delimiter, variable mapping, Every Nth Value, etc.).
    2. Sends the defined Data Command cyclically to the sensor.
    3. Displays the parsed results live in the Data area.
  • This mode allows testing the sensor without interference from other sensors or routines, ensuring the configuration is correct before deploying.
• Debug switch:
  • Activates additional debug information (e.g., framing, invalid characters).
  • Should be used mainly for troubleshooting communication problems.

Notes

• This test window is only available for RS-232, UART1, and UART2 ports.
• RS-485 ports are not tested here, as they are intended for multi-device bus protocols (e.g., Modbus). A dedicated Modbus handling section is used instead.