Double Run Leveling Loops with a Leica Level

The StarDNA converter can read double run leveliing data.  In a double run leveling loop the sequence is:

observe BS and FS 1 and 2
re-setup
Observe BS and FS 2 and 1

move on to the next stage

The STAR DNA converter will look for a message at the start of the gsi file to designate the "Method" that was used.  If that record is not found or if the record does not match the formatting of the data that follows you may see the message "ERROR [Line: X] Record out of sequence; cannot continue" in the log file.  

See below for details from the DNA manual about the "Method" record:

Special code blocks
The levelling technique is tagged by means of a special code block (WI = 41). It is recognizable by the "?" at
the eighth position in the word.

Line levelling method BF 410000+?......1
Line levelling method BFFB 410000+?......2
Line levelling method aBF 410000+?......3
Line levelling method aBFFB 410000+?......4
Check & Adjust 410000+?.....10

For Example:

In the above example, 410015 designates the start of a leveling loop where 15 is the line number.  The part of the record that appears as:+?......1 designates that this is a "Method 1" leveling loop in which the sequence of measurements is: Backsight Foresight.  If you see +?......2 it designates that the sequence of measurements is "Method 2:" Backsight Foresight Foresight Backsight, which is typically used for high order leveling. "Method 2" is typically used for first, second and third order leveling.  The StarDNA converter needs to read which method was used in order to correctly interpret the measurements which will follow.