Burkert Type 8623 - Manual (Page 39)

8623-2-Standard - 37
english
6.6.9 VALV - adaption of controller output signal
Î in the menu item VALV, the
actual value is displayed.
Display of pulse-duty factor of valve
As soon as the controller output is changed by pressing
the
or key, the dispaly changes automatically to
controller output. Onreleasing the key, the actual value
is again displayed.
In this menu item, the controller output can be adapted optimally to the working
range of the actuator currently covered in the application. The proportional valve is
driven by a pulse width modulated (PWM) signal from the controller. Opening of the
valve does not begin at a pulse-duty factor of 0 of the PWM signal, but on account
of the spring force opposing the magnetic force, only at a certain value. This start
of opening depends upon the nominal diameter of the valve, the admission
pressure, and because of temperature dependence of the coil resistance, also on
the coil temperature. The function of the controller can be optimized by having its
output range begin not at 0, but at the start of opening in the current application.
Display of actual value
➔ With this key, the pulse-duty factor of the
proportional valve is increased, i. e. it opens
up to a max. of 100%.
➔ With this key, the pulse-duty factor of the
proportional valve is decreased.
Fig.: Adaption of controller output signal