add non-critical key NT version 2, issue #16

README.md

@@ -31,6 +31,8 @@ On the [Record Evolution Platform](https://www.record-evolution.de/en/home-en/),
 
 ## File format
 
+[Warning: Take a look at [this issue](https://github.com/RecordEvolution/IMCtermite/issues/14) when reading this section regarding the file format.]
+
 A data file of the _IMC Bus Format_ type with the extension _.raw_ is a _mixed text/binary
 file_ featuring a set of markers (keys) that indicate the start of various blocks
 of data that provide meta information and the actual measurement data. Every single

lib/imc_key.hpp

@@ -84,6 +84,7 @@ namespace imc
     // noncritical keys
     key(false,"NO","origin of data",1),
     key(false,"NT","timestamp of trigger",1),
+    key(false,"NT","timestamp of trigger",2),
     key(false,"ND","(color) display properties",1),
     key(false,"NU","user defined key",1),
     key(false,"Np","property of channel",1),