Built-in objects in a configuration

Introduction

For your convenience, a number of predefined objects exist in any configuration that you create. These system objects support basic functions required in any configuration, for example, the Driver object used to generate driver-related error messages in the Alarm List. This topic describes all the system objects.

All predefined objects belong to the Global area. The names of the predefined objects, which are language-independent, must not be changed, except for the Global area.

Driver

The digital object Driver is used to indicate error messages concerning the communication with the PLC displayed in the Alarm List. A number of alarm texts associated with driver communication are reserved for system use. The driver status object automatically uses these texts.

Global

The name of the first (and possibly only) area is Global.

Normally when an object is defined in the system, it belongs to one area only and cannot be referenced in any other area. However, the area named Global is special in the sense that templates and objects defined in that area may be freely used and referenced in all other areas. In a sense the Global area is the smallest area and any other area "larger". In the Global area, only objects defined in that area are "known" while subsequent areas "know" the objects defined in them as well as the objects in the Global area.

Graph

This object is used during supervision when the operator freely selects objects to be displayed in a graph window.

Protect

This special digital object used to protect other objects in the configuration from unauthorized use. Once an object is protected, the rights defined for the current user in User Administration will determine which operations he can perform on the object.

When you create a new configuration, two objects related to user administration are predefined:

The PROTECT template
The Protect object

For further details, read the "Introducing the Protect object" topic.

System

The analog object System monitors two things:

The remaining hard disk space on the server holding the configuration's report folder
Whether the user has access to the report folder

When the High Limit of the System object is exceeded, the system generates the built-in alarm number 94 on the System object. Another more critical alarm - number 95 - is generated when the High Alarm limit is exceeded. The limits can be modified on the Analog tab of the System object..

Read more about the built-in alarms here

When the High Alarm limit is exceeded, ALL LOGGING IS STOPPED.