Digital card for pressure control (strength) in closed ring systems The EWM-P-AA card is a digital card for pressure control (force) in closed ring systems. It manages reduced pressure valves and pressure limiters. It is designed for applications with servant controlled pumps under pressure. The card works as a bypass control module. The reference signal is transmitted directly to the proportional pressure valve by controlling opening and closing. The closed ring compensates only the linearity error. In many cases it is possible to optimize the ring without measuring instruments (only a pressure sensor is required). The power amplifier is integrated. To configure the tab you need the EWM20_SMARTMANAGER software, downloadable on this page. Connection with USB port on the front. The manuals are available upon registration for the reserved area.