Polling And Logging Weight Scale Device to CSV files

A complete guide to read data from weight scales and balances and exporting parsed values directly into a CSV file with your value-column binding and log files rotation

1. Protocol Configuration: RS232 Weight Scale

Communication Type: Passive Listening (Continuous or Print-on-Demand)

Most industrial scales send ASCII strings terminated by a Carriage Return (CR) and Line Feed (LF). Use the software's 'ASCII Data Parser' module and set the data packet signature to ending characters '#0D#0A'. You can then extract the numeric weight by specifying fixed column positions or using a regular expression. Furthermore, the logger contains pre-defined parsers for the most popular scales.

Apply this base configuration for the serial connection:

{
  "port": "COM1",
  "baud_rate": 9600,
  "data_bits": 8,
  "stop_bits": 1,
  "parity": "none",
  "flow_control": "hardware",
  "packet_end": "#0D#0A"
}

2. Database Setup: CSV File

Use the built-in 'Local database' export module. No external drivers are necessary.

Use the following SQL script to create your target table. Do not log continuously into a single CSV file for years. Use the software's 'Log File Rotation' setting to automatically start a new file daily (e.g., `Log_YYYYMMDD.csv`). This prevents files from becoming too large to open in Excel.

No SQL required. You can define a custom header row in the plugin settings to match the exported variables.

3. Protocol-Specific Troubleshooting

• Garbage characters appearing on the screen: This almost always indicates a baud rate or parity mismatch. 9600-8-N-1 is standard, but older Mettler Toledo or Ohaus scales frequently use 2400 baud or 7-Even-1 parity. Check the hardware manual.
• Is it possible to process stable weight only and ignore intermediate values?: Use one of our filter plugins, and for example, ignore all records without the "stable" signature in a data packet.
• Is it possible to process weight values greater that 100.0 kg?: The Expressions filter plugin allows you to using any math expression For example, the following command: DISCARD_DATA_PACKET_IF(WEIGHT < 100).

4. Database-Specific Troubleshooting

• Excel opens the file but all data is squeezed into one column: This is a regional settings issue. In North America, the list separator is a comma (,), but in Europe, it is often a semicolon (;). Ensure the delimiter set in the Data Logger matches the regional settings of the PC opening the file.
• How to get my serial.print to be written into a CSV file: This is the simplest case. The logger does not need to process something in your case. Just enable logging to a file before parsing and change the log file extension to 'csv'.
• Can I write CSV data to a network share to use it from my computer?: Yes, you can specify the destination path as '\\server_name\folder\filename.csv'. If your incoming data is fast, it is better to create a new log file frequently, for example, every hour.