Hello fred974, Just so you know this is not supported as you are going from a 12slot system to a 24slot system. if you wanted to proceed knowing this here is what you would need to do. You will not be able to swap out the MD1220 EMM’s and use your MD3200i controllers.  Most cases that I have seen you will need to reset the controller.  You will need to reset your MD1220 so that it will see your MD3200i controller.  Since you are using an MD1220 you will need to install the MD3220i firmware on the controller so that it can see all 24 slots instead of just 12.  Please let us know if you have any other questions.
Hi, I currently have a Dell PowerVault MD3200i and I need more SSD storage. we were looking at buying a cheap MD1220 as it has a lot more HDD slot than the MD3200i. I would like to know if I can use the MD3200i controller inside the MD1220 so that I can carry on using the iscsi setup that we have at the moment? If possible, will have have to reset the controller or will it simply detect that the chasi has changed? Thank you all in advance
using MD3220i controller in MD1220 enclosure