Siemens SIMATIC ET 200SP - Table of Contents

Counting, measurement and position detection
Function Manual, 12/2017, A5E32009889-AG
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Table of contents
Preface ................................................................................................................................................... 3
1 Documentation guide .............................................................................................................................. 9
2 The basics of counting, measurement and position detection ................................................................ 14
2.1 Overview of modules and properties ...................................................................................... 14
2.2 Basics of counting, measuring and position input (TM Count, TM PosInput,
Compact CPU) ........................................................................................................................ 18
2.2.1 Convention .............................................................................................................................. 18
2.2.2 Overview of applications ......................................................................................................... 18
2.2.3 Recording of count signals ..................................................................................................... 22
2.2.3.1 Counting with incremental or pulse encoder .......................................................................... 22
2.2.3.2 Position input with SSI absolute encoder ............................................................................... 24
2.2.4 Behavior at the counting limits ................................................................................................ 25
2.2.5 Gate control with incremental or pulse encoder ..................................................................... 27
2.2.5.1 Software gate .......................................................................................................................... 27
2.2.5.2 Hardware gate ........................................................................................................................ 27
2.2.5.3 Internal gate ............................................................................................................................ 28
2.2.5.4 Counter behavior at gate start ................................................................................................ 29
2.2.6 Capture (Latch) ....................................................................................................................... 30
2.2.6.1 Capture with incremental or pulse encoder ............................................................................ 30
2.2.6.2 Capture with SSI absolute encoder ........................................................................................ 33
2.2.7 Synchronization ...................................................................................................................... 35
2.2.7.1 Synchronization by digital input .............................................................................................. 38
2.2.7.2 Synchronization at signal N .................................................................................................... 40
2.2.8 Comparison values ................................................................................................................. 43
2.2.8.1 Comparison values and outputs ............................................................................................. 43
2.2.8.2 Switching at comparison values with counter value as reference .......................................... 44
2.2.8.3 Switching at comparison values with position value (SSI absolute value) as reference ........ 48
2.2.8.4 Switching at comparison values with measured value as reference ...................................... 52
2.2.9 Measured value determination ............................................................................................... 54
2.2.9.1 Overview of measuring functions ............................................................................................ 54
2.2.9.2 Measured value determination with incremental or pulse encoder ........................................ 55
2.2.9.3 Measured value determination with SSI absolute encoder .................................................... 59
2.2.10 Hysteresis ............................................................................................................................... 62
2.2.10.1 Hysteresis with incremental or pulse encoder ........................................................................ 62
2.2.10.2 Hysteresis with SSI absolute encoder .................................................................................... 64
2.2.11 Interrupts ................................................................................................................................. 66
2.2.12 Position detection for Motion Control ...................................................................................... 66
2.2.13 Encoder signals ...................................................................................................................... 67
2.2.13.1 24 V and TTL count signals .................................................................................................... 67
2.2.13.2 RS422 count signals ............................................................................................................... 69
2.2.13.3 SSI signals .............................................................................................................................. 71