The Instances collection holds previously executed reports.
<EntityType Name="Report" BaseType="Com.Ingr.Core.V1.DynamicEdmEntityObject" OpenType="true">
<NavigationProperty Name="Instances" Type="Collection(Com.Ingr.Core.V1.ReportInstance)" ContainsTarget="true" />
</EntityType>
Call Instances to see if any report Instances are available. Here are some examples:
GET
https://MyServer.Domain.com/s3d/v1/Sites('MySiteAlias')/Plants('MyPlant')/Reports('{0000EAA5-0000-0000-AA2C-54C7B7541D04}')/Instances
GET
https://MyServer.Domain.com/s3d/v1/Sites('MySiteAlias')/Plants('MyPlant')/Reports('{0000EAA5-0000-0000-AA2C-54C7B7541D04}')/Instances(‘7B7F7782-4047-478B-928C-8C73AA5DD209’)