7
UK
3 Functions and features
3.1 General function description
The device is a two-channel pulse evaluation system for safe overspeed detection�
To do so, it receives the pulse sequences from the pulse pick-ups connected to
the inputs� The device calculates the resulting frequency�
By continuously comparing the input frequency (actual value) and the switch point
(target value) the device promptly detects overspeed of the set switch point�
The NO contacts of the internal relays are connected in series so that the current
paths are not closed before both relays have switched�
Block diagram
The target value is set via 3 switches on the front of the device� The value can be
set in "rpm"/"Hz" (DD110S) or "Hz" (DD111S)�
