Product Description:

The VT-SR7-1X/0/A4VS.500HS SO43A-1608 is an analog valve control module produced by Bosch Rexroth Indramat as part of the VT-SWMA Modules series. Designed for rack-mounted hydraulic drive systems, it converts command signals into controlled coil currents for proportional or servo valves used in industrial automation lines, presses, and test rigs. By integrating signal conditioning and current output on a single Euro-card footprint, the module simplifies cabinet wiring and provides stable analog control in compact hydraulic control assemblies. It is suited to applications where smooth valve response and repeatable spool positioning are important for machine accuracy.

Command inputs are received through an analog reference channel that presents an input resistance of 50 kΩ, limiting loading on upstream controllers. The card follows the Euro-card mechanical standard and plugs into a 32-pin DIN 41612 Form D back-plane connector that carries power, feedback, and enable lines. Internally, the module superimposes a 3 mA dither at 340 Hz on the output current to minimize valve stiction and improve positioning repeatability. During control cycles, it can deliver up to ±60 mA of coil current, allowing direct actuation of most Rexroth proportional valves. This operating method helps the valve respond more consistently during small command changes and low-speed motion.

An external enable contact must be closed, and the circuit expects 700 Ω at this input so wiring faults can be detected. The push-pull bipolar output topology maintains equal sourcing and sinking capability, and the inductive position feedback loop lets the amplifier compare spool position with the command signal for closed-loop accuracy. Power is supplied by dual rails, with a nominal ±24 VDC supply and a separate ±15 VDC supply that must remain within the stated tolerance band for proper operation. Because the design does not include its own voltage regulator, the external power source must remain stable to prevent offset drift in the analog circuitry. This arrangement supports predictable current control while preserving the responsiveness expected in hydraulic servo and proportional valve systems.