Protocol analyzers systems and methods coordinate the capture of network data of interest across multiple chassis. Each chassis has individual blades with accompanying ports and is serially connected to other chassis in the system. Selected ports from each chassis are configured in domains that can be spread across the serially connected chassis and used in coordination to capture network data of interest. A serial protocol containing control signals is used to transmit run, stop, and trigger data between the serially connected chassis and thereby coordinate the activity of ports within each domain. Through the use of the serial protocol the number of wires connecting adjacent chassis is minimized and each of the blades in the multi-chassis systems can be synchronously started, stopped, and triggered at the same time to synchronously capture the network data of interest.