etisserant@0: FUNCTION_BLOCK FWD_REV_MON
etisserant@0: VAR_INPUT AUTO : BOOL ;(* Enable automated commands *)
etisserant@0:   ACK : BOOL ;         (* Acknowledge/cancel all alarms *)
etisserant@0:   AUTO_FWD : BOOL ;    (* Automated forward command *)
etisserant@0:   MAN_FWD : BOOL ;     (* Manual forward command *)
etisserant@0:   MAN_FWD_CHK : BOOL ; (* Negated MAN_FWD for debouncing *)
etisserant@0:   T_FWD_MAX : TIME ;  (* Maximum time from FWD_CMD to FWD_FDBK *)
etisserant@0:   FWD_FDBK : BOOL ;    (* Confirmation of FWD_CMD completion *)
etisserant@0:                        (*   by operative unit *)
etisserant@0:   AUTO_REV : BOOL ;    (* Automated reverse command *)
etisserant@0:   MAN_REV : BOOL ;     (* Manual reverse command *)
etisserant@0:   MAN_REV_CHK : BOOL ; (* Negated MAN_REV for debouncing *)
etisserant@0:   T_REV_MAX : TIME ;  (* Maximum time from REV_CMD to REV_FDBK *)  
etisserant@0:   REV_FDBK : BOOL ;    (* Confirmation of REV_CMD completion *)
etisserant@0: END_VAR                (*    by operative unit *)
etisserant@0: VAR_OUTPUT KLAXON : BOOL ;      (* Any alarm active *)
etisserant@0:   FWD_REV_ALRM : BOOL; (* Forward/reverse command conflict *)
etisserant@0:   FWD_CMD : BOOL ;     (* "Forward" command to operative unit *)
etisserant@0:   FWD_ALRM : BOOL ;    (* T_FWD_MAX expired without FWD_FDBK *)
etisserant@0:   REV_CMD : BOOL ;     (* "Reverse" command to operative unit *)
etisserant@0:   REV_ALRM : BOOL ;    (* T_REV_MAX expired without REV_FDBK *)
etisserant@0: END_VAR
etisserant@0: VAR FWD_MON : CMD_MONITOR; (* "Forward" command monitor *)
etisserant@0:   REV_MON : CMD_MONITOR;   (* "Reverse" command monitor *)
etisserant@0:   FWD_REV_FF : SR ;      (* Forward/Reverse contention latch *)
etisserant@0: END_VAR
etisserant@0: (* Function Block body *)
etisserant@0: (* Evaluate internal function blocks *)
etisserant@0:   FWD_MON    (AUTO_MODE   := AUTO,
etisserant@0:               ACK         := ACK,
etisserant@0:               AUTO_CMD    := AUTO_FWD,
etisserant@0:               MAN_CMD     := MAN_FWD,
etisserant@0:               MAN_CMD_CHK := MAN_FWD_CHK,
etisserant@0:               T_CMD_MAX   := T_FWD_MAX,
etisserant@0:               FDBK        := FWD_FDBK);
etisserant@0:   REV_MON    (AUTO_MODE   := AUTO,
etisserant@0:               ACK         := ACK,
etisserant@0:               AUTO_CMD    := AUTO_REV,
etisserant@0:               MAN_CMD     := MAN_REV,
etisserant@0:               MAN_CMD_CHK := MAN_REV_CHK,
etisserant@0:               T_CMD_MAX   := T_REV_MAX,
etisserant@0:               FDBK        := REV_FDBK);
etisserant@0:   FWD_REV_FF (S1 := FWD_MON.CMD & REV_MON.CMD, R := ACK); 
etisserant@0: (* Transfer data to outputs *)
etisserant@0:   FWD_REV_ALRM := FWD_REV_FF.Q1;
etisserant@0:   FWD_CMD := FWD_MON.CMD & NOT FWD_REV_ALRM;
etisserant@0:   FWD_ALRM := FWD_MON.ALRM;
etisserant@0:   REV_CMD := REV_MON.CMD & NOT FWD_REV_ALRM;
etisserant@0:   REV_ALRM := REV_MON.ALRM;
etisserant@0:   KLAXON := FWD_ALRM OR REV_ALRM OR FWD_REV_ALRM;
etisserant@0: 
etisserant@0: END_FUNCTION_BLOCK
etisserant@0: