One of the big things we’ve tried to do with Trimble Positions, especially in the context of ArcGIS for Windows Mobile, is simplify the workflow. To that end, we introduced field configurations as a way to ‘pre-configure’ sources of real-time corrections (e.g., SBAS/WAAS, single base, VRS) in the office. The office user would provide all relevant connection information and then store this field configuration with a descriptive name (e.g., CalVRS). During project authoring in Mobile Project Center, they would select which field configurations to include in the mobile project as field configurations are global to the current Trimble Positions office database. The field user then only needs to select the desired item from a drop down list to apply that configuration to the receiver. If the real-time correction source is NTRIP-based and requires a username/password, and a username/password has not been stored in the field configuration by the office user, then they will be prompted to provide it. Outside of this prompt, there are no other user interface elements for real-time correction sources in the Trimble Positions Mobile extension.
While this has clear benefits of keeping the user interface simple and not making the field user go through complex configuration steps, it can also cause problems if the field configuration has errors as there is no way to fix them in the field. In general, real-time configurations involve some combination of IP address, port number, NTRIP mount point, username, password, correction datum and datum transformation. Errors in any one of these can cause problems, some obvious (connection failure) and some not as obvious (datum shifts). For this reason, it is important that you validate your field configurations on a mobile device while in the office…maybe twice.