The performance of the positioner of an actuator is adjusted using the TSC parameters. The FSM should reach a new position as quickly and as accurately as possible. Continuous clocking as a result of running above or below the setpoint must by all means be avoided to prevent premature wear on the electronics of the control system. This is achieved by correctly setting the TSC parameters.

The figure below shows the correct functions of the positioner after a setpoint change (setpoint - actual value = W - X):

t_ON

TSC pulse time [ms] (TSC AEE)

t_OFF

TSC break time [ms] (TSC AEA)

W

Setpoint

X

Actual value

X_CONT

Limit value continuous operation

X_PULS

Limit value pulse operation

In case of a major setpoint change (W - X) > X_CONT, the FSM initially goes into continuous operation. Once the actual value has approximated the setpoint sufficiently so that the deviation is X_PULS < (W - X) < X_CONT, the FSM continues to operate in pulse mode. As soon as the actual value has reached the setpoint (W - X) < X_PULS, the FSM comes to a standstill.