TIA Unterprogramm nicht zyklisch ausführen

 CASE #step OF
        0:
           RESET_TIMER(#TON);
           #TSEND_C.REQ := FALSE;
           #io_type_control.active := FALSE;
           #step := 1;
            
        1:
            #TON(IN:=TRUE,PT:=UDINT_TO_TIME(#io_type_control.polling_rate));
            IF NOT #io_type_control.active AND #TON.Q THEN
                #step := 4;
            END_IF;
            
        4:
            #io_type_control.active := TRUE;
            IF #io_type_control.label_to_print = 0 AND #send = #STATUS THEN
                #step := 5;
            ELSIF #io_type_control.#label_to_print <> 0 AND #send <> #STATUS AND #send <> ' '   THEN
                #step := 5;
            END_IF;
            
        5:
            #TSEND_C.REQ := TRUE;
            IF #TSEND_C.BUSY THEN
                #step := 6;
            ELSIF #TSEND_C.ERROR THEN
                #countError += 1;
                #step := 0;
            END_IF;
            
        6:
            #TSEND_C.REQ := FALSE;
            #updateCounter += 1;
            IF #io_type_control.#label_to_print <> 0 THEN
                #io_type_control.label_to_print := 0;
                #io_HMI_print := FALSE;
            END_IF;
            
            IF #TSEND_C.DONE THEN
                #cycles += 1;
                #step := 0;
            ELSIF #TSEND_C.ERROR THEN
                #countError += 1;
                #step := 0;
            END_IF;
    END_CASE;