PLC Device Tag

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  1. Fernhill SCADA
  2. Help
  3. Drivers
  4. Tag Components
  5. PLC Device Tag

Introduction

The PLC Device Tag PLC Device Tag Icon represents a logical link to a device. A device can be any of the following:

Configuration Properties

The PLC Device Tag supports the configuration properties of the Alarm Tag plus these properties:

Property Type Version Description
OutOfService BOOL 3.47 Whether Fernhill SCADA communicates with, or ignores, the PLC Device.
  • False - Fernhill SCADA communicates with the PLC Device.
  • True - Fernhill SCADA ignores the PLC Device.
AlarmSeverity UINT 1.5 The severity of the alarm raised when the PLC device fails.
CommCheckInterval TIME 2.2 The interval between communication status checks to the device. See Interval and Offset for information on how Intervals and Offsets define the time of activities.
CommCheckOffset TIME 2.2 The offset added to the CommCheckInterval to get the actual time of the communication status check. See Interval and Offset for information on how Intervals and Offsets define the time of activities.

CommCheckInterval and CommCheckOffset Properties

The CommCheckInterval and CommCheckOffset properties define when the driver checks the communications to the PLC Device. The result of the communication check is used to determine whether the PLC device is offline or online.

See Interval and Offset for information on how to configure scheduled activities.

Dynamic Properties

The PLC Device Tag supports the dynamic properties of the Alarm Tag plus these properties:

Property Type Version Description
State UINT 1.0 The state of the device
StateDescription WSTRING 1.0 The text description of the device state
ModelName WSTRING 1.9 The detected model name of the target device
CommCheckTimer TimerStatus 2.4 The status of the communication check timer

The State property can have these values:

StateDescription
0Initial state before the driver starts
1The channel reference is invalid
2The device is not responding
3The channel hosting the device is offline
4The reply from the device is not in a recognized format
5The device responded with an error code
6The channel for this device is disconnected or failed
7This device is trying to use a channel that is exclusively allocated to another device
8The device is offline
9A configuration error prevents operation
10The PLC Device is out of service.
15The device is online and communicating

Tag Commands

The PLC Device Tag supports the tag commands of the Alarm Tag.

Relationships to Other Tag Types

The PLC Device Tag builds on the features of these tag types:

The PLC Device Tag is used as a building block for these tag types:

Further Information

Core Tag

To learn about properties common to all tags.

Alarm Handling

To learn about alarm management.

Glossary

For the meaning of terms used in Fernhill SCADA.