How To: Read Log Files¶

The log files contain detailed information about what the application is doing. When something goes wrong, the log file is the first place to look for clues.

Step 1: Open the log directory¶

Open File Explorer.
Navigate to C:\gatekeeper\conveyor\logs\
Expected: You should see files named gatekeeper-YYYYMMDD.log (for example, gatekeeper-20260206.log for February 6, 2026).

If the logs folder does not exist or is empty, the application may not have been running. Check that the application is installed correctly.

Step 2: Open today's log file¶

Find the file with today's date in the name.
Right-click the file and select Open with > Notepad (or any text editor).
Expected: The file contains timestamped log entries.

Tip: If the file is very large, scroll to the bottom to see the most recent entries. You can also use Ctrl+End in Notepad to jump to the bottom.

Step 3: Understand the log format¶

Each line in the log follows this pattern:

2026-02-06 10:30:45.123 [INF] ComponentName Message text here

Part	Meaning
`2026-02-06 10:30:45.123`	Date and time with milliseconds
`[INF]`	Log level (see table below)
`ComponentName`	Which part of the application wrote this message
`Message text here`	The actual log message

Log levels¶

Level	Code	What it means
Debug	`[DBG]`	Very detailed info (usually turned off)
Information	`[INF]`	Normal operations -- things are working
Warning	`[WRN]`	Something unusual but not critical
Error	`[ERR]`	Something failed
Fatal	`[FTL]`	Application crashed

When troubleshooting, look for [ERR] entries first.

Step 4: Search for errors¶

Using Notepad¶

Press Ctrl+F to open the Find dialog.
Type [ERR] and click "Find Next."
Each match shows an error entry.

Using PowerShell (faster for large files)¶

Open PowerShell and run:

Select-String -Path "C:\gatekeeper\conveyor\logs\gatekeeper-20260206.log" -Pattern "\[ERR\]"

Replace 20260206 with today's date.

Step 5: Search for specific keywords¶

If you know what the problem is about, search for related keywords:

Problem Area	Search For
Validation failures	`FAILED` or `IsValid`
Camera issues	`camera` or `NOREAD` or `Cognex`
RFID issues	`RFID` or `EPC` or `FX9600` or `DS9908`
Controller issues	`Arduino` or `Portenta` or `serial`
Import problems	`TEASDALE-IMPORTER` or `NETWORK-FILE-IMPORTER` or `Matthews`
Export problems	`MOJIX-EXPORT` or `MWE` or `AIS`
Validation mode	`[AV50]`, `[CARGILLRFID-VALIDATION]`, `[TEASDALE]`, `[CARGILL-SALT-VALIDATION]`, `[ZFL-VALIDATION]`

Step 6: Get context around an error¶

When you find an error, read the lines immediately before and after it. They often explain what was happening when the error occurred.

Example:

10:30:44.100 [INF] Starting CargillRfid validation with 2 barcodes
10:30:44.150 [INF] Searching RFID cache for EPC matching 2D barcode: ABC123
10:30:44.155 [INF] Global cache contains 0 active tags
10:30:44.160 [ERR] No matching RFID tag found for 2D barcode: ABC123

In this example, the error tells us the RFID cache is empty (0 active tags), which means the RFID reader is not picking up any tags.

Step 7: Check log file age¶

Log files are kept for 14 days by default. If you need logs from more than 14 days ago, they may have been automatically deleted.

To see all available log files: 1. Navigate to C:\gatekeeper\conveyor\logs\ 2. Sort by date to see the oldest available file.

Tips¶

Log files grow throughout the day. A busy site may have log files several megabytes in size.
If you need to send the log file to someone, copy the file rather than moving it. The application continues to write to the current log file.
To enable more detailed logging temporarily, see Verify Configuration -- the Serilog MinimumLevel setting controls log verbosity.