The FX-PCA3613 is capable of using either N2 or the MS/TP communication protocol. Use Release 10.1 of CCT and later to switch the field bus communications protocol in the PCA to either MS/TP or N2 communications protocol. MS/TP is the default communication protocol for all new controllers. Switchable communication protocols (performed in CCT) provide a cost-effective upgrade and modernization path for customers with existing N2 controllers. You must program the PCA3613 controller with CCT, which has similar, but not identical programming capabilities as GX-9100. See the Modernization Guide for Legacy N2 Controllers - Facility Explorer (LIT-12012045) for controller-specific documentation for installation and commissioning support as well as tips for efficient and safe replacement.