IF "o_supplypump" THEN
    "s_flowrate" := "i_flowrate":P;
    #ctime := TIME_TCK();
    "s_targetvolume" := "s_targetvolume" - (#ctime - "s_prevtime") * "s_flowrate";
    "s_prevtime" := #ctime;
ELSE
    "s_prevtime" := TIME_TCK();
END_IF;

CASE "s_state" OF
    "state_init":
        IF "i_restankmid" THEN
            "s_state" := "state_drain";
        ELSE
            "s_targetvolume" := "ui_volume1" * "volumefactor";
            "s_state" := "state_fill1";
        END_IF;

    "state_fill1":
        IF "s_targetvolume" <= 0 THEN
            "s_state" := "state_wait1";
        END_IF;

    "state_wait1":
        IF "s_timer" THEN
            "s_targetvolume" := "ui_volume2" * "volumefactor";
            "s_state" := "state_fill2";
        END_IF;

    "state_fill2":
        IF "s_targetvolume" <= 0 THEN
            "s_state" := "state_wait2";
        END_IF;

    "state_wait2":
        IF "s_timer" THEN
            "s_targetvolume" := "ui_volume3" * "volumefactor";
            "s_state" := "state_fill3";
        END_IF;

    "state_fill3":
        IF "s_targetvolume" <= 0 THEN
            "s_state" := "state_wait3";
        END_IF;

    "state_wait3":
        IF "s_timer" THEN
            "s_state" := "state_init";
        END_IF;

    "state_drain":
        IF NOT "i_restanklow" THEN
            "s_state" := "state_cooldown";
        END_IF;

    "state_cooldown":
        IF "s_timer" THEN
            "s_state" := "state_init";
        END_IF;
END_CASE;

"IEC_Timer_0_DB".TON(IN:="s_state" = "state_wait1" OR "s_state" = "state_wait2" OR "s_state" = "state_wait3" OR "s_state" = "state_cooldown",
                     PT:=T#1s,
                     Q=>"s_timer");

"o_drainpump" := "s_state" = "state_drain";
CASE "s_state" OF
    "state_fill1":
        "o_supplypump" := "i_tank1low";

    "state_fill2":
        "o_supplypump" := "i_tank2low";

    "state_fill3":
        "o_supplypump" := "i_tank3low";

    ELSE
        "o_supplypump" := FALSE;
END_CASE;
"o_valve1" := "s_state" = "state_fill1";
"o_valve2" := "s_state" = "state_fill2";
"o_valve3" := "s_state" = "state_fill3";