stickDesc = valve controlled pressure for JT

makenv tv -driver loop -invar tt -outvar "v motpos/set" \
  -outmin 1 -outmax 0 -prop 1000 -int 100 -mindelta 10 -precision 0.0002

hsetprop /tv label tv_set

makenv table -driver table /tt {
  "tv prop" "1:1000 4:10000"
  "tv int" "1:0.1 4:0.1"
}

hsetprop /tv/set check checktv
hsetprop /tv check checktv

proc checktv {} {
  if {[sct target] > 3} {
    error "[sct target] is too high"
  }
}