OPC HA Read

The OPC HA Read TO can be used to query historical OPC data from servers that support it. The data can be read unprocessed or processed.

General settings

Property	Description
Access Data	OPC connection used to read the OPC HA data.
Read mode	Either Raw/Modified or Processed
Use start time	Defines the start of the period from which data is read. The time refers to the server's timestamp. An explanation of the syntax can be found here: Time offset input options
Use end time	Sets the end of the period from which data is read. The time refers to the server's timestamp. An explanation of the syntax can be found here: Time offset input options
Include OPC Router timestamp	If this option is enabled, the timestamp of the system on which the OPC Router is running is also transferred when a value is read.
Include server timestamp	If this option is enabled, the timestamp of the system from which the values are read is also transferred when a value is read.
Treat Uncertain Quality as Bad	If this option is enabled, a value with the quality Uncertain is treated as a value with the quality Bad.

note

If the end time is before the start time, the data is sorted from old to new. If the start time is before the end time, the data is sorted from new to old.

If the start or end time is not set, the earliest possible time is used for the unconfigured value (DateTime.MinValue).

Read mode-specific settings

Raw / Modified

Property	Description
Read modified data	Specifies whether modified data should be read. Info: Modified data is data that has been changed after it was initially written to the server database.
Read maximum N nodes	Specifies the maximum number of nodes to be read.

Processed

Property	Description
Transfer interval	Specifies the size of the interval to which an aggregation is applied.
Aggregation	This setting specifies which aggregation is to be used for the values.
Use Server Capabilities Defaults	If this option is enabled, the server's default values are used. The settings for “Use Sloped Extrapolation,” “Accepted Bad-Quality Data,” and “Required Good-Quality Data” are then ignored.
Use Sloped Extrapolation	Specifies whether sloped extrapolation should be used.
Accepted Bad-Quality Data	Specifies the percentage of data that may have bad quality.
Required Good-Quality Data	Specifies the percentage of data that must have good quality.

Time offset input options

General

• Relative values are specified with “+” or “-” and the unit without spaces, e.g. -1month
• Absolute values are specified with brackets after the unit, e.g. year(2020)
• Only whole numbers are allowed. The time 1.5 hours ago would have to be specified as -90min or -1h -30min.
• If the year, month, or day are not specified in a relative time specification, the system time is used.
• If the hour, minute, or seconds are not specified, the value 0 is used for them.
• Relative and absolute time specifications can be combined.

Absolute time specifications

Parameter	Explanation	Valid values
second(<second>)	Specifies one second.	0-60 (integer)
minute(<minute>)	Specifies a minute.	0-60 (integer)
hour(<hour>)	Specifies an hour.	0-24 (integer)
day<Day>	Specifies a day.	0-12 (integer)
year(<year>)	Specifies a year.	integer

Relative time specifications

Parameter	Explanation	Valid values
+/-<second>second	Depending on the sign, the specified number of seconds is added to or subtracted from the current time.	Integer
+/-<minutes>minute	Depending on the sign, the specified number of minutes is added to or subtracted from the current time.	Integer
+/-<hours>hour	Depending on the sign, the specified number of hours is added to or subtracted from the current time.	Integer
+/-<days>day	Depending on the sign, the specified number of days is added to or subtracted from the current time.	Integer
+/-<Monate>month	Depending on the sign, the specified number of months is added to or subtracted from the current time.	Integer
+/-<years>year	Depending on the sign, the specified number of years is added to or subtracted from the current time.

Examples

Target	Input
Current day 6 a.m.	hour(6)
One month ago	-1month
First day of the month	day(1)
First day of the previous month	-1month day(1)
One year ago	-1year
First day of the year	month(1) day(1)
First day of the previous year	-1year month(1) day(1)

note

It is not possible to specify the 10th minute of the current hour, because minute(10) returns the time 00:10:00.
This behavior makes it easier to reset the time to zero. For example, on the first day of the month, the time does not have to be manually set to 0 with all parameters.