4 "External Encoder” Technology Object 
 
TOs of S7-1500(T) 
Entry ID: 109743134,    V1.0,    05/2017 
 
 Siemens AG 2017 All rights reserved 
4  "External Encoder” Technology Object 
4.1  General information 
The external encoder technology object present an incremental or absolute value 
encoder for position detection, which is equipped with a PROFINET interface and 
can therefore directly exchange data with the SIMATIC controller. 
Alternatively, a module of the ET 200SP or ET 200MP distributed I/O system for 
position detection, such as TM Count or TM PosInput could also be used here, 
which can communicate with the SIMATIC controller in accordance with the 
PROFIdrive standard. 
 
Figure 4-1 "External encoder” technology object 
 
 
The following motion control instructions can be used together with the external 
encoder: 
  "MC_Power” 
Switching on or enabling the external encoder. 
  "MC_Reset” 
Acknowledging the pending error and warning messages on the external 
encoder. 
  "MC_Home” 
Passive or direct homing of the external encoder in the coordinate system. 
 
4.2  Fields of application 
The external encoder technology object is used for applications where motions 
have to be detected in the SIMATIC controller that are not directly influenced by 
this controller or where a slip is to be expected between drive axle and product or 
material. 
The technology object determines the following current parameters of the recorded 
motion: 
  Current position 
  Current speed (internally calculated from the current position) 
  Current acceleration (internally calculated from the current position)