Table of Contents
Advertisement
Function
Filtering and hysteresis of the current signal
In order to suppress noise of the current signal, the ana-
logue input is sampled equidistantly every millisecond
and a mean value is generated over 0.1 s. This filtering
can be prolonged up to 1 s in the case of a very poor
input signal. However, this also prolongs the response
time to a change at the analogue input.
The current input (4 – 20 mA) operates internally with a
resolution of 10 bit (corresponding to 0.1% of the actu-
ator). This allows the analogue input to detect a change
of 0.02 mA (hysteresis).
If the input signal fluctuates too greatly (owing to noise,
for instance), this high resolution results in constant
corrections of the actuator and butterfly valve (when
mounted onto butterfly valve BV..).
Consequently, the hysteresis may be increased to up to
0.2 mA. The resolution in this case is reduced down to
1% of the actuator accordingly. The maximum resolu-
tion is always set in each case as the basic setting.
IC 40 · Edition 07.18
Priority and running time in operating modes 1 – 10
In operating modes 1 to 10, the actuator is positioned
(0 – 100%) by both digital inputs DI 1 and DI 2. Alterna-
tively, on the IC 40A..A, there is the option of positioning
the actuator with a 4 – 20 mA current signal. Simultane-
ous presets via the analogue input and via the digital
inputs necessitate defining a priority in BCSoft. The
digital inputs have priority by default.
Opening speeds and closing speeds between 0 and
25.5 s can be set for analogue mode. The time always
relates to the distance between the positions at 4 and
20 mA. If the current signal changes more slowly than
the set running time, the actuator follows more slowly
accordingly through to step-by-step movement, see
page 14 (Running times).
49
Advertisement
Table of Contents
