Festo SOEL-RTD-Q50-PP-S-7L, Mounting And Operating Instructions, Page: 31 / 54

Festo SOEL-...1606d English 31
SOEL-
Automatic zero mode
The output characteristic curve 4 – 20 mA is displaced with this function. When the automatic zero mode is activated and Q
1
= +U
B
, the current measured value is equated with the output value of 0% = 4 mA. The incline of the characteristic curve is
maintained and the minimum and maximum values of the characteristic curve are limited by the measuring range.
The distance to the object must be within the measuring range.
Averaging
The measuring result (output signal) is smoothed by averaging. The measured values are read continuously into a memory
and the arithmetical mean is formed. Functions 14 and 15 (page 29) determine the number of measurements (10 or 100) to
be used for averaging.
With a scanning rate of 0.4 ms per measurement, the response time lies between 0.4 ms (without averaging) and 40 ms.
Example of use: When measuring rough surfaces, it is possible to counter-balance fluctuations in measured values.
Illustr. 10 Output characteristics in relation to arithmetical mean
15500273
Response time t(s)
0.4 ms = measured value (no average)
4 ms = averaging with 10 measured values
40 ms = averaging with 100 measured values
Response time
Analogue signal
Factory setting
Autom. zero at 150 mm
Measuring object
I(mA)
100% (20 mA)
50% (12 mA)
0% (4 mA)
+U
B
-U
B
Q
1
100% (20 mA)
0% (4 mA)
80 150 300
mm
t(s)
Illustr. 11
15500148
Illustr. 12
15500147
Direction of movement