Use Indirect tags with remote references

Remote indirect tag references differ from local tag references. The syntax for a remote reference is:

AccessName:Item

where

• AccessName is any valid InTouch Access Name.

• Item is any valid Item Name that is supported by the I/O Server specified in the Access Name definition.

When you use remote references, the server returns a value to the client, not a tag structure. The value includes a time stamp and a quality stamp. Thus, an indirect tag assigned to a remote reference cannot access any tag dotfields other than those related to value, time, and quality. For example, an indirect tag cannot access tag attributes through a remote reference to specify alarm limits.

One possible solution is to create a faceplate with a set of indirect tags. The following figure shows a faceplate to modify the alarm limits for a pump.

In this example, the faceplate uses 10 indirect tags that are associated with an implied .Value dotfield. The alarm faceplate is being redirected to the remote reference tag, IndPumpRPM, on a remote InTouch node named TagServer1. An InTouch Access Name is configured as follows:

To redirect the faceplate to the remote reference tag PumpRPM, run the following QuickScript:

IndPumpRPMName.Name = "TagSource1:PumpRPM.Name";

IndPumpRPMValue.Name = "TagSource1:PumpRPM";

IndPumpRPMHiHiLimit.Name = "TagSource1:PumpRPM.HiHiLimit";

IndPumpRPMHiLimit.Name = "TagSource1:PumpRPM.HiLimit";

IndPumpRPMLoLimit.Name = "TagSource1:PumpRPM.LoLimit";

IndPumpRPMLoLoLimit.Name = "TagSource1:PumpRPM.LoLoLimit";

IndPumpRPMHiHiStatus.Name = "TagSource1:PumpRPM.HiHiStatus";

IndPumpRPMHiStatus.Name = "TagSource1:PumpRPM.HiStatus";

IndPumpRPMLoStatus.Name = "TagSource1:PumpRPM.LoStatus";

IndPumpRPMLoLoStatus.Name = "TagSource1:PumpRPM.LoLoStatus";

The script must run each time the faceplate is redirected. Another solution is to create an InTouch QuickFunction that enables you to write a single script and pass it the name of the remote reference. You can reduce the amount of script coding by using multiple faceplates that call the same QuickFunction.

For example, using a similar set of script commands, you can define a QuickFunction called RedirectAlarmFacePlate:

You can call the RedirectAlarmFacePlate function to handle the entire redirection. To do this, the function must be called by another InTouch QuickScript. For example:

CALL RedirectAlarmFacePlate ("TagSource1:PumpRPM");