[en] The PLF, Mumbai is operated for accelerating a variety of heavy ion beams to high energies ∼ 8-10 MeV/A. The gamma and neutron radiation from the heavy ion accelerated beams in the accelerator area is monitored for safety purposes. The Search and Secure Interlock system has been developed to ensure the safety of personnel working in the LINAC. The controlled access zone, which consists of LINAC Accelerator hall, two experimental halls (Hall-I and Hall-II) and interconnecting tunnel, needs to be checked for human presence and secured to enable the beam operation. To comply with the revised safety standards and for the betterment of the access management, a new system has been designed using Microchip PIC18F family. The search operation in each sub-zone is carried out in a sequential and time bound manner. The search and secure operation involves securing the sub-zone and inserting the door access key in the designated panel in the control room. Only after the completion of the search and secure, the Faraday Cup and subsequently beam operation in the controlled zone, is enabled. The paper will describe design details and operation of the system. (author)