Asaf,
Thanks for contacting National Instruments. As for your question about loading properties only once for a unit instead of for each of the 28 units in your batch, it should be possible although it will require some modifications to work. The Property Loader loads properties for steps, variables, and properties within the current sequence. If you prefer some component of TestStand to only execute once instead of once per unit, then this action should not be part of the client sequence file. However, if we remove the Property Loader from the client sequence file, we also remove the ability to automatically read in and set properties of steps within a client sequence file because we no longer have direct access to those steps, properties, and variables. However, you can set those properties programmatically.
This would require adding a sequence or a step to your process model or overriding the PreBatchLoop model callback. These steps would read in values (probably TestStand FileGlobals) for each of the properties you wish to set in your client sequence file. Then in your client sequence file, before you execute the steps who properties you wanted to read in from the database, you would set each property equal to a file global (for example, if you wanted to read in a high limit for a numeric limit step, you would read that value into a temporary fileglobal, FileGlobals.step1HighLimit. Then as a preexpression for the step, you would have "FileGlobals.step1HighLimit = Step.Limit.High")
This is a stretch because you will have to have a variable defined for each property for each step. In addition, the properties that will be read in will be the same for each instance of your client sequence file running under the batch model. If you wish to have different properties for each unit, then you must have 28 times as many properties - one set of properties for each unique unit - which would get quite cumbersome. You would also have to add the pre-expressions for each step to copy the fileglobal value over to the step's limits.
This would save you the time of reading from your database for each of the 28 units, however it does require having variables defined for each of those values that you wish to read in, so there is a tradeoff.
Let me know if you have more questions.
Regards,
Shannon R.
Applications Engineer
National Instruments
