Hi Linda. Welcome to FMP and the forum There are several options open to you and your choice will be determined by your business needs and workflow processes.
1. Its helpful to know that records in a portal are not committed until the main record is committed. If your layout is based on patient and you have a portal to patient visit, fields you change in the related patient visit records are not committed until the patient record is committed. Now turn off the "Save record changes automatically" in the Layout Setup in Layout mode. When a user clicks outside the portal on the patient record they will be prompted with a "Save changes to this record?" dialog. They can choose from "Don't Save", "Save" or "Cancel". If you then want to make it more explicit what they should do you can add buttons to your layout to "Save" (commit records) or "Don't Save" (revert records).
2. This thread describes a way to work with new records in a modal dialog window before committing them, so that they can be reverted. Modal Windows/Revert Record Instead of viewing the patient visit in a portal it could be viewed in a new window.
3. Another alternative would be to setup global fields for all the patient visit data - a new window or a popover button is opened with the global fields on it. Information is entered. A "Save" button then runs a script to copy the data from each of the global fields into the actual fields.
Hope this helps.
Thanks for all your great suggestions. I will rethink when I update the sensor master. It sounds like I can create a button in the portal for the user to click with a script to add the visit record and update the sensor master. If the visit record already exists, since my key is unique, will the add automatically update the visit record instead?