- Use SL mode (if it is signaled second time)
What is it? I didn't met it... reading

Volhov manual page 44,45,46.
4. VKL. SL-I switch-down. In this case, if the missile misses it will pitch up to fly a maximum climb profile.
4. VKL. SL-II switch-up. With this selected, if the missile misses the target it will continue on a ballistic path.

What is happening with missiles when they reach their max. range? they just stop transmit back to SNR and I know that Volkhov's climb up or goes balistic (depends of the switch "I-62B"), but what with older types? They should explode after maximum amount of time (I think it was 85 seconds)... In this matter what "Vozvrat" do - only cuts the inner transmiter of the missile and leave the missile in self destruction mode (after certain ammount of time) or detonated it immediately?
What about the other complexes? (curious abot S-200the most)...

Depend on missile type.
If the on-board power supply is depleted, than they just go ballistic.
Due to its speed (over Mach6), the Vega missile is simply burn if the autopilot stop functioning...