Modular stacked control loop application system, method of composing a control loop application system and use of a composed control loop application system

A control loop application system comprising a plurality of units of electric circuit boards arranged in a stacked configuration, the control loop application system further comprising a top-level unit and a plurality of additional units, each additional unit having components needed to perform at least one specific function for which the respective additional unit is designed, characterized in that the top-level unit having components such that the top-level unit is able to perform as a standalone unit without requiring the additional units, wherein the system is configured to

• send a grounding signal from the top-level unit on a first channel of a stack connector to a first additional unit in the plurality of additional units,
• shift the grounding signal from the first channel to a next available channel in the stack connector placed between the first additional unit and a second additional unit, determining the position of the second additional unit in the stack by determining the channel on which the grounding signal was received by the second additional unit and transferring the grounding signal to the next additional unit in the plurality of additional units,
• repeating the sending out of grounding signals, the shifting of the received ground signal and the determining of the position by the additional unit for each additional unit in the plurality of additional units have a determined position in the stack.