You can't get rid of all of the dynamic data types as long as you use the Express VIs. To completely eliminate them, you would have to use the lower level functions that the Express VI calls. You can actually look at the code by right clicking on the Express VI and selecting Open Front Panel.
You have provided a default name and Create function. If you just click OK when the dialog comes up, then it will create that file. If the file exists, you will be prompted to replace it. I think you'll have an error though unless the mode is Create or Replace. With Create, the user has tp specify a new file each time or you come up with a method of automatically creating the file name. A common technique is to get the Date/Time string and append that to a path constant.
With Write File or Write to Spreadsheet, then is no automatic creation of a time stamp. The higher level file write functions like Write LabVIEW Measurement File have that and it gets it from the dynamic data type. I would suggest you try it both ways. Use a single Merge Signals to get all of the dynamic signals togeterh and wire the output to the Write LabVIEW Measurment File. The format of the file created is more or less fixed unless you want to do a lot of modifications to the WLMF function. It's also a bit slower because it also opens and closes the file each iteration. At one end, you have extreme ease of use but little flexibiltiy. At the other, more coding involved but a great deal of control on the format of the output.
