Automatic Centre Mode; Maximum Hold Mode - Pepperl+Fuchs 3RG7256-3NQ00-PF Instructions De Service Et De Montage

Automatic centre mode

The output characteristic curve 4 – 20 mA is displaced with this function. When the automatic centre function is
activated and Q = +U
1 B
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.
Analogue signal
100% (20 mA)
50% (12 mA)
0% (4 mA)
+U
B
Q
1
­U
B
Illustr. 13
15500146

Maximum hold mode

When maximum hold mode is activated and Q
signal and stores it.
If Q = ­U , the last maximum value is transmitted at the analogue output.
1
B
Example of use: determining the maximum value of a shaft
The minimum value can be determined by inverting the analogue output characteristic (see function no. 16 and 17).
100% (20 mA)
0% (4 mA)
100% (20 mA)
0% (4 mA)
+U
B
Q
1
­U
B
Illustr. 15
15500153
36
, the current measured value is equated with the output value of 50% = 12 mA. The incline of
1
1
2
1
A B A
100% (20 mA)
50% (12 mA)
0% (4 mA)
t(s)
Illustr. 14
15500145
= +U , this function detects the maximum value of the measuring
B
14 mA
1
2 8 mA
2
A
B
B
3RG7256­3NQ00­PF Distance sensor ­ 068­13787 / 45­3489 ­ Stand: 03/2011
operating instructions
250 400 500
Q = +U = Sample. Collect measured values
1 B
Q = ­U = Display. Last maximum of analogue signal at
1 B
analogue output
Mounting and
Autom. centre at 400 mm
mm
750