Product Description:

The VT-SR7-1X/A4VS.750HS is an electronic control card produced by Bosch Rexroth Indramat within the VT-SWMA Modules series. It installs on a standardized 3U rack to condition analog command signals and supply regulated drive current to electrohydraulic devices on automated machinery. By combining signal processing, voltage regulation, and relay switching on one board, the module simplifies cabinet wiring and supports repeatable motion or pressure tasks in industrial automation environments. This type of card is commonly used where proportional hydraulic components must respond consistently to low-level control signals.

The analog input channel presents an impedance of 50 kΩ, helping prevent loading of upstream controllers while converting setpoint values. Power is supplied from a symmetrical rail centered on ±24 VDC, and the onboard regulator maintains auxiliary outputs at 150 mA for downstream electronics. For improved valve linearity, the board injects a dither signal; its carrier is fixed at 340 Hz, and the amplitude is limited to 3 mA, so spool hysteresis is reduced without overheating the coil. The mechanical layout follows the Eurocard format and occupies only 100 × 160 mm in the card cage, which helps conserve rack space and allows the module to be removed without dismounting adjacent boards.

Output relays energize through a coil that measures 700 Ω, ensuring low hold current and minimal internal heating. The drive stage can source or sink up to ±60 mA of valve current, enabling proportional actuation across the full stroke of compatible solenoids. For installations subject to fluctuating plant supplies, operation remains stable up to ±28 VDC before overvoltage shutdown engages. Field wiring terminates on a backplane connector that conforms to 32-Pin DIN 41 612 Form D, providing a keyed interface that guards against misalignment during insertion. A discrete voltage regulator is included, so the board does not rely on external conditioning for its ±15 V reference rails.