Attached is a simple shell script file for monitoring the existence of a file in linux. Download the XML file and go to Admin --> Script templates and import the XML file. While saving it, provide the file name as the name of the template. On the command line, provide the file name along with the full path of the file you want to monitor as an argument.
For ex.
sh ${FileName}.sh /root/opm_be.txt
where /root/opm_be.txt is the file name along with the path and save it.
If the file exists, the value returned will be '0' and if it doesn't, it will return '1'. Associate the script with the devices and check if it helps.
Pravin