VT-SR2-1X/1-60

The VT-SR2-1X/1-60 analog control card is manufactured by Bosch Rexroth Indramat for use in the VT-SWMA Modules series. It is intended for installation in automation cabinets where printed-circuit plug-in modules manage proportional functions, logic interlocks, and solenoid actuation. The board translates low-power command signals into stable current for field coils, while its integrated relay section provides isolated switching. A single card can therefore supervise fluid-power or general machinery stages without requiring external interface hardware.

Its physical format follows the Euro-Card standard, and signal and power lines are presented through a DIN 41612, Design D edge connector that locks into backplane headers. The average current draw from the cabinet supply is only 0.15 A, which helps with sizing shared power rails. The active circuitry operates from a ±24 V supply that is internally divided by a precision regulator. A 5 kHz oscillator drives the modulation stage to maintain consistent coil energization. Incoming commands are processed through discrete analog amplifiers rather than microcontrollers, avoiding conversion delays when the module feeds its 60 mA solenoid output.

The input stage has an impedance of 50 kΩ, preventing excessive loading of upstream signal sources. The board remains functional at supply levels as low as ±22 V, and overvoltage protection is provided up to a ceiling of ±28 V. The relay coil has a resistance of 700 Ω and operates at a pickup voltage of 24 V. Its contacts close within 4 ms to route the regulated ±15 V rail or external lines as needed. Once activated, the relay output feeds the connected field device, while the solenoid channel supplies a fixed current of 60 mA to a hydraulic or pneumatic valve. The high-impedance input limits the current demanded from the command source, and the regulated internal rails support consistent analog processing during normal operation.