Aveva Historian Reader Documentation

Version: 1.1.1 

Retrieved: 2025-10-09 15:15:14

Aveva Reader

This module retrieves data from an Aveva historian database. It can get the values added since the last request as well as values within a specified time window, starting from an offset back in time.

Settings

Name Requirements Purpose Default
Target Property Length: 1-64 The property to write the result into. data
Offset Number The time in ms back in history to collect data until, leave this and window size at 0 to get all data from the last query  
Window Size Number The size of the time window to get, ending at the offset  
Tags List of strings The Tags to get, leave empty to get all tags  
Tags collection (Resource) Resource containing tags    
Include vValue Boolean If true, the vValue will be included in the result  
Retrival Mode   The mode to retrieve the data, see the Historian documentation for more information  
Filters List of objects A list of statements that are translated into a SQL WHERE statement, if many filters are used each row must match every one of them (AND)  
Force UTC boolean Force the time to be in UTC instead of local time  

Filters

Column The column to get data from
Operator The operator to use
Data The data to compare to
Behaviour The behavior to use: if Static the data field is used as is, if Property the data field is used to match a property on the incoming message

Credential

This module needs a credential of type 'Connection string' to connect to the database server. A minimal connection string is shown below. Depending on the setup of your database server additional parameters may be needed. Please consult the documentation for your server.

Server=tcp:192.168.0.5;Database=crosser;User ID=demo;Password=crosser123;

Retrieval Modes

When using other retrieval modes than 'Full' you typically need to provide additional conditions. For example, with 'Delta' mode you can specify conditions on one or both of the 'wwTimeDeadband' and 'wwValueDeadband' parameters. You do this by adding 'Filters'. Let's say we only want to get changes ('Delta' mode) on tag values, but no more often than every 5 seconds. Then we can add this filter:

wwTimeDeadband Equals 5000 (the time unit is ms)

Read more about the available parameters and how they impact the different retrieval modes in the Aveva Historian documentation.

Resource File

Each needs to have a 'name' tag. in addition you can add additional tags to the resource file, these tags will be used to attach metadata to the result

{
	"tags": [
		{
			"name": "heater_001.sensorfault",
			"machine": "alfa"
		},
		{
			"name": "heater_002.sensorfault",
			"machine": "beta"
		}
	]
}

will give output in the format of

{
    "dateTime":"2024-09-05T13:19:30.034+00:00",
    "machine":"alfa",
    "tagName":"heater_001.sensorfault",
    "value":0
}

Input

A query will be sent to the database each time a message is received

Output

An output message will be sent each time the module receives a message. The result of the query will be added to the incoming message on the configured [Target Property]. If the target property exists on the incoming message it will be overwritten.

Name Type Description
[Target Property] Object array Each measurement is represented as an object in the array
crosser.success Boolean True if the message was stored properly in the database, otherwise False
crosser.message String Contains a error message in case the insert failed, if the insert is successful this property is not set.

Example

Prerequisite: A database with three tags usage_idle, usage_irq and usage_nice

#Settings

Target Property: data
Tags: usage_idle, usage_nice, usage_irg
Offset: 0
TimeWindow: 0

# Output

{
  "data": [
        {
            "DateTime": "2020-08-20T14:47:00Z",
            "TagName": "usage_idle
            "Value": 0.2
        },
        {
            "DateTime": "2020-08-20T14:47:00Z",
            "TagName": "usage_nice"
            "Value": 0.5
        },
        {
            "DateTime": "2020-08-20T14:47:00Z",
            "TagName": "usage_irq"
            "Value": 0.1
        }
  ]
 }

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