ServiceElements
System functions can be executed in encapsulated services FB_MTP_ServiceControl. The service bundles various procedures, parameters and report values. The execution takes place in procedures. Procedures are different execution variants of a service.
One example would be filling a tank: the service could be called Filling
. The procedures of this service could be called Volume_Filling
and Duration_Filling
with different parameters to fill a certain volume or for a certain time.
Services describe the function and execute it in procedures, so a service must always have at least one procedure FB_MTP_Procedure.
The following parameters can be transferred to the procedures for execution:
Configuration parameters
Configuration parameters are assigned to all procedures of a service. They are typically set during commissioning.
Procedure parameters
Unlike configuration parameters, procedure parameters can be assigned to one or more procedures of a service. They are typically set before a service is started.
Report values
ReportValues
are assigned to one or more procedures of a service. They can be used, for example, to document important process values.