The EHA is a highly integrated system developed by Thomas to meet the demanding requirements of communal vehicles, concrete pumps, cranes and tractors. It comprises two proportional pressure reducing valves, installed in a housing together with an electronic control unit and a redundant Hall sensor system. The sensor system allows to precisely adjust and monitor the position of the main spool in the customer's system. A convenient error diagnostics function and a fast software adaptation make the EHA a reliable, flexible and safe control unit. The product can be used up to a Performance Level PL=c according to DIN EN ISO 13849.