The development of high-efficiency longwall complexes in underground mining enforces the introduction of new control systems for the operation of a powered roof support. The most important stage when creating a new control system for a powered longwall system is to determine the time dependencies between the setting off of the function and its actual implementation by the control elements of the control system. Electro hydraulic control of the powered roof support has a number of advantages as compared to the manually operated distributor blocks. The most important are: higher supply pressure, reduction of the amount of force needed to override the support, the ability to adjust the power parameters to absorbency of the support’s actuators and their number, modular construction of control and executive dividers allowing customization construction of electro hydraulic control units and requirements resulting from the construction of the section. The presented research is focused on the analysis of time relations between the setting off of the control function and its actual implementation. This is the time from the moment of supplying power to the solenoid valve until the solenoid valve is opened. This dependence is of extremely significant as it determines the effectiveness of the entire control system.