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Tag Database

Table Of Contents

The “Tag Database” chapter in DataTalk software is a tool for creating and editing the tag structure. You can create, edit, and delete tags and modify their data types. Additionally, the tag database allows for reading and displaying real-time data from PLCs, serving as a centralized location for all project tags.

The Tag Database allows you to specify limits applied to the whole system. For example, the animations have a trigger limit, and the same goes for the alarms. This means that if you decide to change the limits, for example, from 50 to 100, and you do it in the tags database, it should be applied in the whole project everywhere that tag is used.

Tag Operations

One of the basic features is adding / removing / modifying tags in the Tag Database.

Log groups

Tags Database allows you to create log groups, which are then used to log data out of the tags which are assigned to these groups, which can then be displayed in the charts or tables.

The tags values are logged ONLY if the value of the tag is changed, the period only specifies how often is DataTalk going to check with the connection if the value has changed

Limits

Tags database allows you to specify limits by which the system will check whether the read value of the tag is within the specified limits if not, then it can be used to trigger an alarm

Read Values

The tags database allows you to read/display live values from the PLC. This function only reads “expanded” connection tabs.

Sem bych dal asi gif jak se vytvořit tag v tag db

FieldDescription
Value This field will display live value read out of the PLC if you click “Read Values.”
Address Specify the data point address in the PLC.
Type The data type of a tag.
Access Limits a user’s access to specific tags.
Label Serves for internal notes; more fields for each specific language will appear if more languages are specified.
Scale Specifiy a value’s read/write scaling, which means the values can be automatically divided/multiplied by the default.
Limits Specify tag limits for alarms/alerts.
Log Check if you want this value to be logged.
Log GroupsSpecify a value’s read/write scaling, which means the values can be automatically divided/multiplied by the default.
Unit Specify whether the output value is, for example, in °C or any other unit.
Format Specify default number decimal points.
Gateway ?

What’s a “tag”?

Adding a tag to a SCADA system represents a programmatic variable from a PLC.

A tag is an object that contains a value, a timestamp, and quality information. It often represents real-world values from physical objects, such as sensor readings or motor speeds.