Spectra Precision FAST Survey Reference Manual - Manual (Page 58)

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 Special Codes:
In addition to the codes that you add to the Feature Code List, there are some predefined code
suffixes that you may use to end lines or start curves. For example, FL END could end the fence line, with “END”
being a predefined special code. The need to append codes is one reason that the "END" button on your data
collector is useful, to move to the END of the existing description so you can append a special code. You can
substitute new codes for default codes, such that “..” can be substituted for “END” to end a line. To substitute a
code, highlight it and enter the substitution characters at the bottom of the screen, in the "Code" entry box. The
special code suffixes can also be entered as prefixes, as in PC EP (for start curve) rather than EP PC. Special
Codes should be separated from your actual feature codes by a space. However, the alias of “..” can go right up
against the feature code as in “FL..”. The special codes are described below.
ST & END
: Start and End Line. Some users prefer codes such as BL for Begin Line and EL for End Line,
and ".." is another example of an "end line" code. You only need either to start or end lines to get new lines.
You don't need to use both the start and end line coding. If you code 3 EP points as EP ST, EP, EP then the
nexst new line can be EP ST again. Or you could just end the line as in EP, EP, EP END, then start again with
EP. Another separate technique to generate unique lines is to add a number to the code, as in EP1, EP1, EP1.
Then if you code EP2, EP2, EP2 a separate line will be drawn. In this case, you don't even need to use the
start or end special codes. This allows you to mix the codes up as in EP1, EP2, EP2, EP1. In this case, the
EP1 codes will connect and the EP2 codes will connect. See also the discussion below on "Auto-Detect Code
Pattern" for techniques of cross-sectioning roads and other linear features. Within Configure, the option "Use
Unique IDs for Linework" makes use of the EP1, EP2, EP3 concept by incrementing the appended number
each time a new line is started using the line start code (eg. ST) or the line start icon. With "Use Unique" on,
the EP code becomes EP1 when you start a line, and if you use EP again and start another line, the code
becomes EP2, etc. In this case, the ST code is retained (redundant but harmless) as in EP2 ST, EP2, EP2.
PC & PT
: Used to specify the point of curvature (PC) and point of tangency (PT) of a curve. If you are taking
shots on a curve, use PC to specify the beginning of the curve and PT to specify the end of the curve. The PC
special code will activate a 3-point arc automatically, so use of the PT code in a 3-point arc is redundant and
therefore it is not necessary. You can even do a reverse curve by entering the PT instead as PC. However, if
you are picking up a meandering stream or tree line, PT is useful to end the curving feature, and the program
will “best fit” a curve through all the surveyed points between the PC and PT codes.