Telemetry server static data references

Static data references are used when the objects have already been defined in the Telemetry Server. Static data reference syntax is common to all protocols in Telemetry Server, whereas dynamic data reference syntax varies by protocol. Static data references can use any of the following syntaxes:

Telem_Server_<ScopeName>:<Item>

Telem_Server_<ScopeName>:<Item>.<Property>

Telem_Server_<ScopeName>:<Item>.<DatabaseAggregate>

Telem_Server_<ScopeName>:<Item>.<DatabaseAggregate>.<Property>

Telem_Server_<ScopeName>:<Item>.<Method>

Telem_Server_<ScopeName>:<Item>.<DatabaseAggregate>.<Method>

Where

• <ScopeName> is by default the name of the computer where the Telemetry Server instance is installed. You can customize the "ScopeName" field in the Telemetry Server to accommodate redundancy.

• <Item> is the location of the database item.

• <Property> is the name of the property tag that you want to reference. If you omit <Property>, the tag uses the default property for the defined database item or aggregate. The default property for an item or aggregate varies according to the type of item or aggregate. For example, the default property for a point is CurrentValue.

• <Database Aggregate> is the name of the database aggregate that has the required property. Database Aggregates are extensions to a table in the database and they have their own name, table, properties and methods.

• <Method> is the name of the method that you want to reference. Method static tags are write-only. Attempting to read a method tag generates an error.

  • Method static tags are write only. Writing to a method tag invokes the method, and thus triggers the associated action. Attempting to read a method tag generates an error.

  • Only methods with zero or one arguments are supported in static tags. When you write to a method tag with zero arguments, the value being written is discarded. When you write to a method tag with one argument, the value being written is passed as the argument to the method. Therefore, the argument must match the value.

Static data reference examples

Example of the static data reference syntax:

Telem_Server_Node12:Group01.Group02.Tank_Level

You can trigger the Telemetry Server to call a dial-up outstation by invoking the one shot method. Writing to this tag invokes the “OneShot” method on the “PSTN” database aggregate of an outstation called “Group.Outstation.”

Telem_Server_XXXXX:Group.Outstation.PSTN.OneShot

You can apply an override to an analog point by invoking the override method. Writing a value to this tag invokes the “Override” method on the point “Group.AI_1” to change the point to the specified value. Overriding must be enabled on the point:

Telem_Server_XXXXX:Group.AI_1.Override