This may be addressed better in the Mechanical HVAC or the NFPA forum in Engineering Codes. Perhaps the interlock can be software if the system is a life-safety fire system to operate fire dampers, sequence HVAC blowers, etc. Refer to NFPA 72 requirements. The fire codes are likely directed by the local authority having jurisdiction for the job site. The fire panel likely requires high reliability and long-term battery backup specifically for NFPA 72 applications.