A common use case is when the openPDC is used to collect measurements from PMUs and then forward the measurements to another PDC. An example of this is a TO collecting data and sending to an ISO. In many cases, the ISO only wants to receive a subset of the measurements for each PMU. For example, the ISO may prefer to receive on the positive sequence phasors - not the A, B and C phases.
 
The User Interface for creation of a virtual device for an output stream is extremely clumsy and unforgiving. If the user makes any errors in the long and tedious process, they have to delete the device and start over. Otherwise, if there are any errors (such as unmapped measurements) the resulting data stream gets marked as invalid in the C37.118 protocol.
 
Consider a PMU where 8 phasors are to be passed on. The user must create a device. Then, on the Manage Output Stream Device Phasors form perform 8 separate "clear", type phasor name, select phasor type, Save, Ok operations to create the 8 phasors. The screen for creating phasors does not allow any poorly created phasor to be deleted (you have to delete the device and start over). A similar set of operations is needed for each desired analog or digital value.
 
Next select measurements to be added on the Add Measurements for Output Stream form. Then, for each added measurement (16 for the 8 phasors, plus the frequency, DF, SF), individually select the measurement on the Manage Output Stream Measurements form. Type (or paste) the virtual device id in place of the <UNASSIGNED> text. Select Update and select ok. Be careful not to accidently select Delete for a measurement. You get no warning and the measurement gets deleted and there is no way (short of deleting the device and starting over) to add it in again.
 
Also note that the virtual device is associated with a single output stream. If it is desired to output the same subset to multiple streams, it is necessary to repeat the enterire procedure.
 
 
I suggest an alternate interface that allows the user to add a virtual device corresponding to a real PMU with approximately a single click. A form could be brought up showing each measurement mapped to the correponding PMU measurement. The user could then deselect any that don't map correctly before
selecting save or update.