Described herein are various technologies for monitoring the backplane of a control system and detecting modifications of the control system (e.g., removal of modules, firmware updates, etc.). A monitoring device includes a field programmable gate array (FPGA), and is connected to the backplane of the control system. The monitoring device receives signals, by way of the backplane, that are communicated among modules connected to the backplane. The monitoring device detects a modification to the control system based upon the received signals.