Message Log Overview

The Message Log feature lets you view messages logged with the Message Log Functions. You can use this feature to debug, troubleshoot, write messages to users, trace the progress of a program, and for general logging. Messages are written to a log file (extension .log) on the controller file system in the /Automation1/MessageLog/ directory. The Message Log continuously monitors the log file for new messages and shows them in this format:

{timestamp} - {message severity} - {message content}

For more information about how to view logged messages, see the Viewing Program Messages section of the Programming module page. This module is part of the Develop workspace.

Because the log file is on the controller file system, any application that has access to the controller can write messages to it. This includes custom applications that use one of the Automation1 APIs. Messages persist in more than one session of Automation1 applications and exist until MessageLogClear() is called or the log file is manually deleted.