Specify the OPC Property

Each field on a configuration Form comprises an OPC property and is assigned a unique OPC identifier. When you add a custom extra field, Geo SCADA Expert automatically assigns the next available OPC identifier to that field. The identifier is visible in the OPC Property field in the Edit Field window (see Add or Modify an Extra Field).

If you have multiple Geo SCADA Expert systems (databases), you might have a 'design' system on which you set up and test initial configuration and configuration changes. You might then use the Import and Export features in Geo SCADA Expert to deploy that configuration to the other systems. If so, it is imperative that if an extra database field has been added directly to any of those other systems in the past that its OPC identifier matches that of the same custom extra field on the system from which the configuration is about to be imported. On each system into which you are about to import the configuration, check the value of the OPC Property setting on the previously manually added custom extra field. If the field is found to have a different OPC identifier to the same field on the system from which the configuration is about to be imported, change the value in the OPC Property setting so that the two match. You would typically do this on the target system so that the setting matches that of the same custom field on the source system. You only need to perform this procedure on any custom extra fields that have previously been added directly to the system(s) into which you intend importing configuration. If the custom extra fields have always been added by copying the database from one particular system, then this stage will not be required. This is because the OPC identifier of each field on the target systems will already match that of the same property on the source system (the system from which the configuration was copied).

When you display the Edit Field window, you can ascertain the custom field's OPC identifier value:

• OPC Property—When you add a new custom field, Geo SCADA Expert automatically pre-populates this property with the next available OPC identifier to those already in use in the database.

  You can modify the value in the field if need be. For example, so that it matches the OPC identifier of the same custom field on a system from which you are about to import configuration into this one. With any changes that you make to this field, Geo SCADA Expert checks that the value is a valid OPC identifier value and that it is not already in use for another OPC property in the database.

When adding a new custom field, after viewing and/or editing this value, continue to define the other field settings as required.