Siemens SIMATIC OpenPCS 7 User Manual

Aggregate function Description
OPCHDA_MINIMUM Obtains the lowest value of the raw data for the specified
period.
OPCHDA_MAXIMUMACTUALTIME Obtains the highest value and the time stamp of the raw data
for the specified period.
OPCHDA_MAXIMUM Obtains the highest value of the raw data for the specified
period.
OPCHDA_DELTA Obtains the difference between the first and last value of the
raw data of the specified period.
OPCHDA_REGSLOPE Obtains the slope of the linear regression of the raw data for
the specified period.
OPCHDA_REGCONST Obtains the value of the linear regression of the raw data at
the start time.
OPCHDA_REGDEV Obtains the standard deviation of the linear regression of the
raw data for the specified period.
OPCHDA_VARIANCE Obtains the variance of the raw data for the specified period.
OPCHDA_RANGE Obtains the difference between OPCHDA_MAXIMUM and
OPCHDA_MINIMUM of the raw data for the specified period.
OPCHDA_DURATIONGOOD Obtains the period in which the quality of the raw data was
good. The period is entered in seconds.
OPCHDA_DURATIONBAD Obtains the period in which the quality of the raw data was
bad. The period is entered in seconds.
OPCHDA_PERCENTGOOD Obtains the portion during which the quality of the raw data
was good as a percentage.
OPCHDA_PERCENTBAD Obtains the portion during which the quality of the raw data
was bad as a percentage.
OPCHDA_WORSTQUALITY Obtains the worst quality of the raw data for the specified
period.
6.4.6 Overview of supported functions
Introduction
The following tables list the functions supported by the OPC HDA server. These functions can
be used by the OPC HDA client for data exchange. Additional information is available in the
"OPC Historical Data Access Specification 1.20" of the OPC Foundation.
Function Description
ReadRaw Specifies the raw data, its quality and its time stamp for the specified period.
ReadProcessed Returns the calculated value, the quality of the value and the time stamp
for the specified period. The calculated value depends on the selected
aggregate function.
ReadAtTime Specifies the raw data, its quality and its time stamp for a specific point in
time. If no value exists, it is interpolated for this point in time.
ReadAttribute Returns the attributes of the item and the time stamp for the specified period.
OpenPCS 7 interface
6.4 OPC Historical Data Access (OPC HDA)
OpenPCS 7
Function Manual, 05/2012, A5E02780178-02 51

Siemens SIMATIC OpenPCS 7 Specifications

General

Brand	Siemens
Model	SIMATIC OpenPCS 7
Category	Control Systems
Language	English