Examples Of Use - Pepperl+Fuchs 3RG7256-3NQ00-PF Instructions De Service Et De Montage

Mounting and
operating instructions
4. Insert reference object of known width in measuring range.
Warning: LED "OK" (Good target) must light up on both sensors.
5. Configure the second device as the master. Activate function no. 25 (page 34).
Warning: The sensor can only be configured as a master when the object is inside the measuring range of both
sensors (see point 4).
6. The analogue value on the master corresponds with the measured reference width and the 50% value (autom.
centre function) of 12 mA. All function settings on the master are based on the difference in thickness.
7. Feed objects into the measuring range to start measurement.
8. The measured value provides the difference to the reference width and is at the analogue output of the master.
The analogue output of the slave supplies the distance to the object.
We recommend resetting sensors to factory setting (function 22, page 34) before configuration of
sensors as master or slave.
In differential measurement mode, resolution and linearity must be multiplied by 2, because 2
sensors are used.

Examples of use

Double layer detection
Detection of double layers of boards or plates, e.g. in wood or plastic
processing (Illustr. 20). The problems caused by an uneven feeding
of plates and a considerable variation in the distance to the sensor
can be avoided with the aid of differential measurement. The plate
thickness can be determined with the master output signal.
Double layers are detected when threshold values for the thickness
of the object (functions 1 and 2, page 32) have been previously set
on the master.
Thickness measurement for large wooden boards
Checking the thickness of wide wooden boards. The solution is to
align both sensors (Illustr. 21). The set distance is measured and is
then available for measurement of object width.
Slave
The analogue output on the master sensor supplies information on thickness.
Illustr. 21
15500150
3RG7256­3NQ00­PF Distance sensor ­ 068­13787 / 45­3489 ­ Stand: 03/2011
Nominal dimension
Plates
Illustr. 20
15500151
Master
Control
Control
39