The billing reports function will only work if you have the optional (and free) FPDF library installed. It generates a set of PDFs (one for each of the Groups selected) that summarises the instrument and consumable usage. These PDFs are desgined to provide group leaders with information about how the instruments have been used over the billing period.
The PDFs include four sections:
As there are multiple different PDFs generated, it is not possible to deliver them through the web browser, so they must be emailed. You may elect to have these PDFs emailed to the email address recorded for the currently logged in user or to the email address recorded for the leader of each group. It's always an idea to email them to yourself first and then to the supervisors at a later stage once you've checked that everything has worked OK...