[gmx-users] gmx convert-tpr, gmx check Q?

[badamkhatan togoldor]

Dear GMX-Users,I have a technical question regarding to the gmx convert-tpr and gmx check.  I have a little bit doubt in that.  Simulation was calculating 5.000.000 steps, 10ns and it has stopped due to the some cluster time limit. So I want to continue it from that stopped step. So,
gmx convert-tpr -s pro.tpr -f pro.trr -e pro.edr -o pro1.tpr -until 10000 ( it means that when checked the gmx check the .tpr file it says 4688 step and 1 ps. From this step until finish to 10 ps?)     And also 10,000 ps  is 10 ns right? then why gmx check gave me the 1 ps ? or is it 1 ns ?  
 Item        #frames Timestep (ps)
Step          4688    1
Time          4688    1
Lambda      4688    1
Coords       4688    1

gmx mdrun -deffnm $pro -append -cpi which check point file I should apply pro.cpt  OR pro_prev.cpt ? 
I would highly appreciate for any answers! Thanks 

Regards,Khatnaa