If you are wanting to exclude a single element of a device from Iris monitoring, you can start by going to the Edit Mnemonics page.
Once the mnemonic lists opens up, you will be able to search for the element by specifying the device name and interface.
After finding the mnemonic that you are searching for, delete it by clicking on the bin icon.
To undelete the menmonic at a later stage, click the 'eye' icon to show you all the mnemonics that have been deleted. You will be able to undelete the mnemonic from here. Click here for an article on how to undelete in Iris. The same principles in this article apply throughout Iris when undeleting.