This paper presents the problem of modelling simultaneous periodic output feedback control design to control the first two vibration modes of a flexible smart cantilever beam. The entire structure is modeled by finite element method using a piezoelectric beam element which includes a piezoelectric sensor and actuator dynamics. Simulation results demonstrate that a single controller can be employed to control the first two vibration modes for six different sensor/actuator locations along the beam. Application of simultaneous control introduces a redundancy in smart structure control.