674ef1e6_Automation__X_10_Web_Interface__Description
[File] x10.log [Description] 
This is where the program writes its log entries. Each log file entry contains the current date and time, the status of the masterswitch, the user's host name (or IP address if the host name is not available), and the actual command sent to the communications link. A setting in the configuration file lets you determine if you want new entries added to the top or bottom of the file. NOTE: File locking is not implemented here. Therefore, if your web page is getting a lot of simultaneous traffic, it is possible that some commands will not appear in the log.
Scott Crevier's Home Automation: X-10 Web Interface
Description