Data Collection Systems
A collection system is a collection of sites that share a communications system, typically via a Gateway, to the host system. Use this screen to view the system details and to view the details of the data sources that are included in each system.
Collection System Details
| Property | Description |
|---|---|
|
System |
System description |
|
Entry method |
Indicates whether data collection in the system is Automatic (using |
|
Status |
For automatic systems, indicates whether the system is Running or Stopped |
Click on a collection system link to see the included Data Sources.
Data Sources, Tables and Tags
About Data Sources
A data source is a source of measurement data collected from your sites. In a SCADA system the data sources typically consist of sites with remote terminal units (RTUs) that store data in tables and tags.
About Tables
An RTU stores data in a set of tables in which each cell can contain the data from a tag. Tags are addressed by specifying the table number, then the row and column number. The table structure is also stored in the application database. Each table stores a specific data type.
The SYSTEM table is stored only in the host database and does not correspond to a table on the RTU. By convention, this table is given the table number 200. The SYSTEM table is commonly used to hold calculated tags, and status flags such as the communications status flag.
Click on the table link to view the layout of tags in the table.
About Tags
Tags are data items associated with a site. Tag values may be read from a sensor or other input device connected to an RTU, or can be calculated from other data. In SCADA Systems, tags are organised in tables which are stored in RTU memory from where they are copied to the host database. Additional tags may be stored only in the host database in a System table.
Click on the tag link to go to the Tag Details screen for that tag