direction of servo walls

Submitted by zamir on Fri, 11/01/2013 - 07:30

Hello all,

I cannot get the servo wall to move in the -Z direction, even if I use a negative target_val. This is how I issue the command:

variable lid_force equal -1400
fix lid0 all mesh/surface/stress/servo file LIGGGHTS_files/STL_files/in/p_lid.stl type 2 move 0 0 ${lid_height} com 0. 0. ${lid_height} ctrlPV force dim z target_val ${lid_force} vel_max 0.01

When I print the z coordinates of the wall, f_lid0[9], they are strictly increasing over time no matter what values I input for target_val.

I really want my servo controlled walls to move in the negative z direction. Please help.

FYI, I am using liggghts v2.3.8.

Thanks,
Zamir

PS: I edited the command a bit, my first post was inaccurate.