When purchasing licenses for InduSoft Web Studio SCADA software, it’s important to know an approximation of how many tags you will need for your SCADA project. It’s equally important to understand how InduSoft Web Studio counts tags, so that you can come up with an accurate estimate for your project’s needs. InduSoft’s license levels depend primarily on the maximum number of application tags required for the application.
Each tag is a “variable” capable of holding an independent value, such as “PressureTankA”, “TemperatureOver1”, “StateMotorC”, and so forth. The following rules apply for InduSoft’s tag count:
– The tags created by the user. Application or Project tags in the SCADA software are counted against the license limit. However, the System Tags, created automatically for any project, are not counted against the license tag limit (e.g.: Time, Date, UserName, and so forth).
– The tag count does not depend on the data type supported by each tag (Boolean, Integer, Real, or String).
– The same tag can be configured in many interfaces, and it still counts as only one tag. For example, the same tag can be configured on Screens, Trend worksheets, Alarm worksheets, Driver worksheets, OPC worksheets, and this will not affect your tag count.
– Any tags created for the project are counted against the license limit, even if they are not linked to an external device (e.g.: PLC) via communication drivers, OPC, or any other task. In other words, as soon as the tag is configured in the application, it is counted against the license limit.
– VBScript variables are commonly used to manipulate temporary values used in calculations. VBScript variables can be used in any VBScript interface of the SCADA software (VBScript tasks, Global Procedures, Graphic Scripts, Screen Scripts, and so forth) and they do not count against the license tag limit in the SCADA software.
– Each array position counts as one tag because it holds an independent value. For example, a tag configured with 3 array elements counts as three tags (Tag, Tag, and Tag).
– Each member of a class tag counts as one tag because it holds an independent value. For example, a class tag with 2 members counts as two tags (Tag.MemberA and Tag.MemberB).
– Class tags configured as arrays count as the number of array positions multiplied by the number of members. For example, a class tag with 2 members and configured with 3 array elements counts as six tags (Tag.MemberA, Tag.MemberA, Tag.MemberA, Tag.MemberB, Tag.MemberB, and Tag.MemberB).