Devices, systems and methods for network traffic monitoring for a process control network are disclosed. The exemplary system may include a connection to a physical media and a connection to a media access controller of the process control network. The system may also include a filter having a position identifier, a data comparator, a counter, and an access controller. The position identifier may determine the position of relevant data within a packet. The data comparator may compare the relevant data to predetermined criterion. The counter may count the amount of packets transmitted to the media access controller that do not match the predetermined criterion during a specified period. The access controller may pass packets to the media access controller if the relevant data matches the predetermined criterion or a predetermined amount of packets have not been transmitted.