This is not immediately relevant to software installation, but is mentioned here for completeness. Each tag in the WebAccess database is assigned to one Area and given one security Level. Each User is assigned a security Level for each Area. The default Level is 0 (the lowest).
In order to change the value of a tag, the User's Area must match the Area of the Tag AND the User's Level in that Area must be equal to or greater than the security Level of the tag.
If the user's Level and Area do not match the tag's Area and Level, a Popup Dialog Box will appear prompting the user to Login as a new user. In a Web Browser, this new log in is temporary and applies only to changing the selected tag.
WebAccess has 31 user defined Areas and 4 special Areas (Local Tag, View Tag, Tag Field and ViewDAQ).
Level 127 is administrator level and is required to change Field Tags (for example, change alarm limits from the point detail. All Field Tags require Level 127 in order to change them. Examples of Tag Fields include Alarm Limits, Description, SPANHI, SPAN LO, and ENG UNITS.
Tag Field level = 127 allows a user to change online configuration parameters (e.g. Alarm Limits).
View Tag level = 127 allows a user to change System Parameters (e.g. enable simulation mode).
ViewDAQ level defines an exit password Level for a ViewDAQ window. The users ViewDAQ level must be greater or equal to the Exit Password Level defined for that ViewDAQ window. This is designed form preventing users form closing all Control Windows locally on the SCADA Node and form stopping the SCADA Node kernel (locally). ViewDAQ level = 127 allows the user to create, modify and Save Display groups (including the Exit Password Level).
For all the details regarding security, please refer to Chapter 8 - Users, Passwords & Security in the Engineering Manual.