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Entry type: FAQ Entry ID: 100660265, Entry date: 09/05/2014

SIMOTION: Diagnostic functions for PROFINET and PROFIBUS

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What system functions can be used to diagnose PROFINET and PROFIBUS?


Guidelines for the diagnostic system functions to be used regarding the particular application in which they are used
List of the possible communication relationships between higher-level and subordinate devices:


Description of the various use cases in which the diagnostic system functions can be used:

Use case A:
A higher-level controller attempts to determine the state of a lower-level device. The diagnostic system functions are called in the user program of the controller.
Functions to determine the state that are appropriate for this particular application (refer to the diagram):

Case 1 (Master/controller > IO-Device/DP-Slave):

  • _getStateOfSingleDPSlave
  • _getStateOfAllDPStations
  • _getStateOf AllDPSlaves (only for DP slaves)
  • _getStateOfIO
Case 2 (Master/controller > I-Device/I-Slave):
  • _getStateOfSingleDPSlave
  • _getStateOfAllDPStations
  • _getStateOfIO
Case 3 (Master/controller > Shared I-Device):
  • _getStateOfSingleDPSlave
  • _getStateOfAllDPStations
  • _getStateOfIO
Use case B:
A lower-level device attempts to obtain information about the state of a higher-level controller. The diagnostic system functions are called in the user program of the lower-level device. In this particular case, the lower-level device is an I-Device or a shared I-Device

Case 4 (I-Device/Shared I-Device > Master/controller)
  • _getStateOfIO (in this particular case, only provides information about the data transfer state, on a slot-granular basis)
Use case C:
The diagnostic system functions are called in the user program of a controller. The controller is at the same time an I-Device. Here, a distinction has to be made as to which address area is to be interrogated. If the area assigned to the controller is interrogated, then use case A applies.  If the area assigned to the I-Device is interrogated, then use case B applies.


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