With multiple files specified for the -f option:
Concatenates several energy files in sorted order. In the case of double time frames, the one in the later file is used. By specifying -settime you will be asked for the start time of each file. The input files are taken from the command line, such that the command gmx eneconv -f *.edr -o fixed.edr should do the trick.
With one file specified for -f:
Reads one energy file and writes another, applying the -dt, -offset, -t0 and -settime options and converting to a different format if necessary (indicated by file extentions).
-settime is applied first, then -dt/-offset followed by -b and -e to select which frames to write.
Options to specify input and output files:
-f [<.edr> [...]] (ener.edr) (Input)
-o [<.edr>] (fixed.edr) (Output)
-nice <int> (19)
Set the nicelevel
-b <real> (-1)
First time to use
-e <real> (-1)
Last time to use
-dt <real> (0)
Only write out frame when t MOD dt = offset
-offset <real> (0)
Time offset for -dt option
Change starting time interactively
Sort energy files (not frames)
Remove free energy block data
-scalefac <real> (1)
Multiply energy component by this factor
Stop on errors in the file