Closed-loop control is handled by the DTC-500 digital controller, which runs three independent feedback loops so the machine can regulate to a force setpoint, a displacement setpoint, or an extension setpoint, depending on what your method calls for.

In force control, the controller continuously compares the commanded load profile to the live force signal from the load-measuring transducer, then adjusts the servo-hydraulic output to correct any error. This is the mode typically used for proof loading, load holds, and other load-driven steps.

In displacement control, the controller uses position feedback from the machine’s displacement measurement (encoder or grating ruler input) and modulates the actuator to follow a target displacement rate, ramp, or hold. This is commonly used for seating, approach, and certain compression or fixture-driven routines.

In extension control, the controller closes the loop on the extensometer signal so the specimen strain or extension is what drives the actuator response. This is the mode typically selected for yield and elongation-focused tensile methods where strain rate control matters. If you want to confirm the best control mode and sensor configuration for your specific standard and specimen, use learn more or request a quote.