Monitor a process or wait for event

For Excel to do batch or monitoring type of work it must wait and check for data in a loop.

It's better coding to have an event that kicks off code but this isn't always possible.

For full batch the Windows Job Scheduler is useful to open the Excel file and the auto_open or Workbook_open event can start running the code.

Some issues to deal with are:

waiting without taking up too many resources

How often to check for incoming data

How to send back results

Making sure Msgbox or errors doesn't stop the code

Being able to monitor the batch process

Dealing with the case when you open an Excel file and you don't want it to open in the batch window

Using computer while batch process is running