TechArchive

Original article date: July 1999

Introducing the photoelectric sensors that allow the user to tailor the sensor to suit the application

With more and more demands placed on components for today’s high speed production techniques, engineers are faced with a vast array of different sensors to detect product in the latest complex packaging designs.

Pepperl + Fuchs offer a series of “Software Enhanced Capability” photoelectric sensors that allow the user to tailor the Sensor to suit the application and not tailor the application to suit the sensor possibly causing further mechanical problems further down the line.

If all you need is an easily programmed, high quality sensor then this series will ako fit the bill.

Simplicity in setting up was paramount in the early days of design. The sensors can be set up by pressing the two buttons, which form the membrane keypad, and entering the “teach-In” mode, bringing the relevant object into the detection range, pressing any of the buttons to accept and the sensor is then set up.

At the heart of this sensor series is a powerful microcontroller which is capable of more sophisticated tasks. Each unit in the series has an integrated infra-red interface which when connected to any PC or laptop running the OPUS 2.0 software package or the optional hend-held terminal, can open up the factory pre-set parameters to user friendly precision adjustment to suit the application.

This progrim can then be saved on hard disk or floppy disk for future use or transferring to another sensor with the same set up, saving time in re-programming. Stock levels can be reduced because it’s the program that might change for each application and not the sensor.

When programming via computer, the familiar Windows format of the software makes life amazingly easy. Just use the mouse to select appropriate listing fields and adjust accordingly. With no more than a click you can set the function of the switch output and the failure warning output (an indication when either the lens is dirty and the sensor is not receiving enough light back or has been knocked out of alignment), switching hysteresis, timer functions and on-board logic functions, saving inputs into PLC’s.

Another programmable parameter is the pulse frequency selection. A classic example of mounting units close together is the possibility of mutual interaction there-by giving false switching because the units “talk” to each other. When selecting frequency 1, 2 or 3 this can be avoided.

One of the more interesting parameters that can be activated is the keypad lock. This can be used to stop the “fiddle factor” by unauthorised personnel, the buttons can be pressed but no access can be gained to the programming.

Another big plus factor designed into the F22 and the F44 is the clever, re-positional plug connector. This connector can be rotated through 90 degrees to give the most convenient cable exit.

Sophisticated these units are, but delicate they are not. All the electronics, microprocessor and light emitter and receiver are mounted inside an unbroken skin ofheavy-duty synthetic resin. As a result the series attains a protection class of 1P67.

The series consists of the compact and proven F22, the F44 for greater range and more flexibility and the F66 for glass or plastic light guides (fibre optics).

Sensing principles include Direct Detection, Background Suppression, Retro-reflective or Reflex and Through-Beam with Laser, AS-Intefface versions and special clear object versions also available this series offers the user a very flexible solution to most sensing solutions.