Kepserverex Tags

 🏷️ What Are Tags in KEPServerEX?

In KEPServerEX, a Tag is a named data point that represents a value from a connected industrial device — such as a PLC, sensor, robot, or flow meter.

It acts like a variable (just like in programming), which holds real-time data such as temperature, pressure, motor speed, switch status, etc.

📦 Components of a Tag

Each tag in KEPServerEX contains the following important attributes:

Attribute Description Example

Name User-defined tag name Motor_Temperature

Address Device-specific memory location DB1.DBD10

Data Type Type of data INT, REAL, BOOL

Scan Rate How often the tag reads from device 1000 ms (1 second)

Access Type Read-only or Read/Write R/W

Initial Value Optional default value 0

Description Notes about the tag "Motor Temp in °C"

🧭 Tag Hierarchy in KEPServerEX

KEPServerEX organizes tags within this structure:

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Channel

 └─ Device

     └─ Tag Group

         └─ Tag

🔹 Example:

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Channel: Siemens_TCP

  └─ Device: S7_1500_PLC

      └─ Group: Motor_Data

          └─ Tag: Motor_Temperature

📂 Types of Tags in KEPServerEX

1. Device Tags

Definition: Tags that directly map to a memory address in the connected device.

Usage: Used for reading/writing values to/from a PLC, RTU, sensor, etc.

Example: PLC1.Tank_Level = value at memory DB2.DBW20

2. System Tags

Definition: Tags provided by KEPServerEX itself, not linked to any device.

Purpose: Provide server status, connection status, diagnostics.

Examples:

_System._DeviceStatus

_System._ScanRate

_System._TimeStamp

3. Advanced Tags (Requires Plug-in)

Definition: Logical or calculated tags created by combining or transforming other tag values.

Purpose: Perform arithmetic, conditional logic, or string operations.

Examples:

Avg_Temp = (Temp_Sensor1 + Temp_Sensor2)/2

If Motor_Speed > 1000 Then Overload = TRUE

4. Dynamic Tags

Tags that are created programmatically at runtime using the REST API or other dynamic data sources.

🔁 Read/Write Tag Operations

Action Description

Read Get the current value from the device

Write Send a new value to the device

Subscribe Monitor changes (used by OPC/SCADA clients)

⚙️ How Tags Work (Behind the Scenes)

A driver connects to a device (e.g., Siemens S7 PLC).

The tag in KEPServerEX maps to a memory address in the PLC.

KEPServerEX polls the device at a defined scan rate.

Applications (like SCADA, MES, Cloud) read/write to that tag using OPC UA, MQTT, REST, etc.

🏭 Real-World Example (JLR Manufacturing)

Use Case Tag

Paint Booth Temperature PaintBooth.TempSensor1 (Device Tag)

Robot Joint Angle Robot1.JointAngle1 (Device Tag)

Welding Overheat Condition WeldOverheat = Temp1 > 300 (Advanced Tag)

PLC Connection Status _System._DeviceStatus (System Tag)

Line Status to MES AssemblyLine1.Status (Read/Write Tag to MES)

📈 Visual Example

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Device: Siemens S7-1500 PLC

└── Tag Group: EngineAssembly

    ├── Tag: EngineTorque → DB3.DBW10 → INT

    ├── Tag: MotorSpeed → DB3.DBD20 → REAL

    └── Tag: OverheatFlag → DB3.DBX30.0 → BOOL

🔐 Security & Access Control

Each tag can have access permissions:

Read Only

Write Only

Read/Write

Tag-level access can be controlled by user roles in KEPServerEX Security Policies.

📊 Benefits of Using Tags in KEPServerEX

Benefit Explanation

Standardization Tags abstract device data in a vendor-neutral format

Real-time Monitoring Tags provide instant visibility into process variables

Interoperability Same tags are used across SCADA, MES, Cloud

Logic and Control Tags can automate decisions using advanced functions

Security Control access to critical data points

🔧 Tools to Manage Tags

KEPServerEX Configuration Tool (GUI)

OPC Quick Client (for tag testing)

Tag Import Wizard (bulk import from Excel)

Export/Import Tags (for backups and deployment)