ABB TB820V2 CEX Bus ModuleABB TB820V2 CEX Bus Module Overview The ABB TB820V2 (Complete Model Number: 3BSE013208R1) is a CEX bus module designed to connect AC 800M controllers to I O systems. This module supports the CEX Bus (Controller Expansion Bus) for connecting various I O and communication interface modules, allowing the AC 800M controller to expand its functionality and handle more complex control tasks. 1. Main Functions and Specifications Characteristic Data Product