1 FUNCTION_BLOCK FWD_REV_MON

     2 VAR_INPUT AUTO : BOOL ;(* Enable automated commands *)

     3   ACK : BOOL ;         (* Acknowledge/cancel all alarms *)

     4   AUTO_FWD : BOOL ;    (* Automated forward command *)

     5   MAN_FWD : BOOL ;     (* Manual forward command *)

     6   MAN_FWD_CHK : BOOL ; (* Negated MAN_FWD for debouncing *)

     7   T_FWD_MAX : TIME ;  (* Maximum time from FWD_CMD to FWD_FDBK *)

     8   FWD_FDBK : BOOL ;    (* Confirmation of FWD_CMD completion *)

     9                        (*   by operative unit *)

    10   AUTO_REV : BOOL ;    (* Automated reverse command *)

    11   MAN_REV : BOOL ;     (* Manual reverse command *)

    12   MAN_REV_CHK : BOOL ; (* Negated MAN_REV for debouncing *)

    13   T_REV_MAX : TIME ;  (* Maximum time from REV_CMD to REV_FDBK *)  

    14   REV_FDBK : BOOL ;    (* Confirmation of REV_CMD completion *)

    15 END_VAR                (*    by operative unit *)

    16 VAR_OUTPUT KLAXON : BOOL ;      (* Any alarm active *)

    17   FWD_REV_ALRM : BOOL; (* Forward/reverse command conflict *)

    18   FWD_CMD : BOOL ;     (* "Forward" command to operative unit *)

    19   FWD_ALRM : BOOL ;    (* T_FWD_MAX expired without FWD_FDBK *)

    20   REV_CMD : BOOL ;     (* "Reverse" command to operative unit *)

    21   REV_ALRM : BOOL ;    (* T_REV_MAX expired without REV_FDBK *)

    22 END_VAR

    23 VAR FWD_MON : CMD_MONITOR; (* "Forward" command monitor *)

    24   REV_MON : CMD_MONITOR;   (* "Reverse" command monitor *)

    25   FWD_REV_FF : SR ;      (* Forward/Reverse contention latch *)

    26 END_VAR

    27 (* Function Block body *)

    28 (* Evaluate internal function blocks *)

    29   FWD_MON    (AUTO_MODE   := AUTO,

    30               ACK         := ACK,

    31               AUTO_CMD    := AUTO_FWD,

    32               MAN_CMD     := MAN_FWD,

    33               MAN_CMD_CHK := MAN_FWD_CHK,

    34               T_CMD_MAX   := T_FWD_MAX,

    35               FDBK        := FWD_FDBK);

    36   REV_MON    (AUTO_MODE   := AUTO,

    37               ACK         := ACK,

    38               AUTO_CMD    := AUTO_REV,

    39               MAN_CMD     := MAN_REV,

    40               MAN_CMD_CHK := MAN_REV_CHK,

    41               T_CMD_MAX   := T_REV_MAX,

    42               FDBK        := REV_FDBK);

    43   FWD_REV_FF (S1 := FWD_MON.CMD & REV_MON.CMD, R := ACK); 

    44 (* Transfer data to outputs *)

    45   FWD_REV_ALRM := FWD_REV_FF.Q1;

    46   FWD_CMD := FWD_MON.CMD & NOT FWD_REV_ALRM;

    47   FWD_ALRM := FWD_MON.ALRM;

    48   REV_CMD := REV_MON.CMD & NOT FWD_REV_ALRM;

    49   REV_ALRM := REV_MON.ALRM;

    50   KLAXON := FWD_ALRM OR REV_ALRM OR FWD_REV_ALRM;

    51 

    52 END_FUNCTION_BLOCK

    53