Survey data is entered in the form of text files. You can use any text editor you like for this, so long as it has the capability of writing a plain ASCII text file. The data format is very flexible; unlike some other cave surveying software, Survex does not require survey legs to be rearranged to suit the computer, and the ordering of instrument readings on each line is fully specifiable. So you can enter your data much as it appears on the survey notes, which is important in reducing the opportunities for transcription errors.
Also all the special characters are user-definable - for example, the separators can be spaces and tabs, or commas (e.g. when exporting from a spreadsheet), etc; the decimal point can be a slash (for clarity), a comma (as used in continental Europe), or anything else you care to choose. This flexibility means that it should be possible to read in data from almost any sort of survey data file without much work.
Survex places no restrictions on you in terms of the ordering of survey legs. You can enter or process data in any order and Survex will read it all in before determining how it is connected. You can also use the hierarchical naming so that you do not need to worry about using the same station name twice.
The usual arrangement is to have one file which lists all the others that are included (e.g., 161.svx). Then cavern 161 will process all your data. To just process a section use the filename for that section, e.g. cavern dtime will process the dreamtime file/section of Kaninchenhöhle. To help you out, if all legs in a survey are connected to one another but the survey has no fixed points, cavern will 'invent' a fixed point and print a warning message to this effect.
It is up to you what data you put in which files. You can have one file per trip, or per area of the cave, or just one file for the whole cave if you like. On a large survey project it makes sense to group related surveys in the same file or directory.
Blank lines (i.e. lines consisting solely of BLANK characters) are ignored. The last line in the file need not be terminated by an end of line character. All fields on a line must be separated by at least one BLANK character. An OMIT character (default '-') indicates that a field is unused. If the field is not optional, then an error is given.
Survex has a powerful system for naming stations. It uses a hierarchy of survey names, similar to the nested folders your computer stores files in. So point 6 in the entrance survey of Kaninchenhöhle (cave number 161) is referred t