The two-stage ramp function is used, for example, for start-up mode of specific firing plants. The control release then increases the setpoint in two periods with different increase speeds:

Periods of the ramp function

W

Setpoint

T

Time

P1

Period 1

P2

Period 2

y-P1

Increase factor period 1 (RAMP-F1-Value)

y-P2

Increase factor period 2 (RAMP-F2-Value)

x-P1

Period limit 1 (RAMP-L1 value)

x-P2

Period limit 2 (RAMP-L2 value)

As soon as the signal for the start of the ramp function is received via the digital input channel (control release), the setpoint is overwritten with the current actual value. Then a check determines the period in which the current setpoint is located. The setpoint is then modified by the increase speed that was defined for that period.

As soon as the end of period 2 is reached, the ramp ends and the previously adjusted setpoint is restored. While the ramp is active, control is also active and attempts to regulate to the current setpoint.