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Entry type: Application example Entry ID: 109480157, Entry date: 01/15/2016

Measuring input with Time-based IO

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Implementing a measuring Input with the technology modules TM Timer DIDQ 16x24V or TM Timer DIDQ 10x24V.

The technology modules TM Timer DIDQ 16x24V or TM Timer DIDQ 10x24V are used to implement a measuring input as follows:

The task is to measure the length of objects on a running material line using a sensor. The sensor is used to generate a rising sensor signal edge at the beginning of the object and a falling edge at the end. These signal edges are acquired via a measuring input including the associated material line positions. The difference of both points in time yields the length of the object.

The figure below shows a schematic overview of the most important components of the solution:

The technology module TM Timer DIDQ is connected to the SIMATIC CPU via an interface module by means of a isochronous PROFINET connection. The objects on the continuous material line are detected with a sensor connected to the technology module TM Timer DIDQ. The technology module TM Timer DIDQ provides the acquired signals with highly precise time stamps and forwards them to the SIMATIC CPU. There, the positions
assigned to the time stamps are determined and forwarded to the user program.
Once the positions for a rising edge and a falling edge of the sensor, i.e. for the beginning and the end of a passing through object have been determined, the length of the object can be determined in the user program by calculating
the difference.

  Documentation (1,8 MB)
 Registrierung notwendig  STEP 7 V13 SP1 Library for a measuring input with position output (1,1 MB)
 Registrierung notwendig  STEP 7 V13 SP1 Library for a measuring input with output of only the time stamp (1,1 MB)
 Registrierung notwendig  STEP 7 V13 SP1 Project as application example (4,0 MB)

Realizing the technologcal function "Measuring input", you could use the Technology Object of TIA Portal V14. You will find additional information to this Technology Object in TIA Portal Online Help or in the operation manual "Motion Control"  of TIA Portal (Entry ID 109481326).

Last changes 
V1.2: new input at FB for time correction

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