(*
TYPE

    MB1_STATE : (
        WAITING_FOR_START := 0,
        CLIENT_INITIALISATION := 10,
        CLIENT_START := 100,
        WAITING_FOR_ACTIVE_OR_ERROR := 150,
        ACTIVATE_F3_FIRST := 1000,
        WAITING_FOR_ACTIVE_FISRT := 1005,
        CHECK_FIRST_VALUE := 1010,
        DEACTIVATE_F3_FIRST := 2000,
        WAITING_FOR_INACTIVE_FISRT := 2005,
        ACTIVATE_F3_SECOND := 2010,
        WAITING_FOR_ACTIVE_SECOND := 2015,
        CHECK_SECOND_VALUES_READ := 2020,
        DEACTIVATE_F3_SECOND := 2100,
        WAITING_FOR_INACTIVE_SECOND := 2150,
        FINISH_OR_RESTART := 2200,
        FINISH_DEACTIVATE_CLIENT := 2500,
        FINISH_WAITING_FOR_INACTIVE := 3000
    ) := WAITING_FOR_START;

END_TYPE
*)

CASE iState OF

    MB1_STATE#WAITING_FOR_START:
        IF xStart = TRUE THEN
            iState := MB1_STATE#CLIENT_INITIALISATION;
        END_IF;

    MB1_STATE#CLIENT_INITIALISATION:
        (* Client *)
        udtExample.udtClient.xActivate := FALSE;
        udtExample.udtClient.xAutoAck := FALSE;
        udtExample.udtClient.strServer_IP := '192.168.1.166';
        udtExample.udtClient.iPort := 5020;
        udtExample.udtClient.xUDP_Mode := FALSE;
        udtExample.udtClient.tTimeout := TIME#5s;
        udtExample.udtClient.tReconnectDelay := TIME#1s;

        (* FC3 function block *)
        udtExample.udtMB_TCP_FC3.xActivate := FALSE;
        udtExample.udtMB_TCP_FC3.iMT_ID := 1;

        iState := MB1_STATE#CLIENT_START;

    MB1_STATE#CLIENT_START:
        udtExample.udtClient.xActivate := TRUE;
        iState := MB1_STATE#WAITING_FOR_ACTIVE_OR_ERROR;

    MB1_STATE#WAITING_FOR_ACTIVE_OR_ERROR:
        IF (udtExample.udtClient.xActive = TRUE) THEN
            iState := MB1_STATE#ACTIVATE_F3_FIRST;
        END_IF;
        IF(
            udtExample.udtClient.xError = TRUE
            AND xRestartIfError = TRUE
        ) THEN
            udtExample.uiRestartIfError := udtExample.uiRestartIfError + UINT#1;
            iState := MB1_STATE#CLIENT_INITIALISATION;
        END_IF;

    MB1_STATE#ACTIVATE_F3_FIRST:
        udtExample.udtMB_TCP_FC3.xActivate := TRUE;
        udtExample.udtMB_TCP_FC3.uiQuantityOfRegisters := UINT#1;
        (* udtFC3.arrRegisterValues = ARRAY [1..125] OF WORD *)
        udtExample.udtMB_TCP_FC3.wStartRegister := WORD#0;
        iState := MB1_STATE#WAITING_FOR_ACTIVE_FISRT;

    MB1_STATE#WAITING_FOR_ACTIVE_FISRT:
        IF (udtExample.udtMB_TCP_FC3.xActive = TRUE) THEN
            iState := MB1_STATE#CHECK_FIRST_VALUE;
        END_IF;
        IF(
            udtExample.udtMB_TCP_FC3.xError = TRUE
            AND xRestartIfError = TRUE
        ) THEN
            udtExample.uiRestartIfError := udtExample.uiRestartIfError + UINT#1;
            iState := MB1_STATE#CLIENT_INITIALISATION;
        END_IF;

    MB1_STATE#CHECK_FIRST_VALUE:
        (* Modbus server has to deliver these values! *)
        IF (udtExample.udtMB_TCP_FC3.xError = FALSE)
            AND (udtExample.udtMB_TCP_FC3.arrRegisterValue[1] = WORD#16#07D0)
        THEN
            iState := MB1_STATE#DEACTIVATE_F3_FIRST;
        END_IF;

    MB1_STATE#DEACTIVATE_F3_FIRST:
        udtExample.udtMB_TCP_FC3.xActivate := FALSE;
        iState := MB1_STATE#WAITING_FOR_INACTIVE_FISRT;

    MB1_STATE#WAITING_FOR_INACTIVE_FISRT:
        IF (udtExample.udtMB_TCP_FC3.xActive = FALSE) THEN
            iState := MB1_STATE#ACTIVATE_F3_SECOND;
        END_IF;

    MB1_STATE#ACTIVATE_F3_SECOND:
        udtExample.udtMB_TCP_FC3.xActivate := TRUE;
        udtExample.udtMB_TCP_FC3.uiQuantityOfRegisters := UINT#5;
        udtExample.udtMB_TCP_FC3.wStartRegister := WORD#0;
        iState := MB1_STATE#WAITING_FOR_ACTIVE_SECOND;

    MB1_STATE#WAITING_FOR_ACTIVE_SECOND:
        (* Deactivate FB after first data received *)
        IF udtExample.udtMB_TCP_FC3.xNDR = TRUE THEN
            udtExample.udtMB_TCP_FC3.xActivate := FALSE;
        END_IF;
        IF
            udtExample.udtMB_TCP_FC3.xActive = TRUE AND
            udtExample.udtMB_TCP_FC3.xError = FALSE
        THEN
            iState := MB1_STATE#CHECK_SECOND_VALUES_READ;
        END_IF;

    MB1_STATE#CHECK_SECOND_VALUES_READ:
        (* Deactivate FB after first data received *)
        IF udtExample.udtMB_TCP_FC3.xNDR = TRUE THEN
            udtExample.udtMB_TCP_FC3.xActivate := FALSE;
        END_IF;
        (* Modbus server has to deliver these values! *)
        IF
            udtExample.udtMB_TCP_FC3.xError = FALSE AND
            udtExample.udtMB_TCP_FC3.uiByteCount = UINT#10
        THEN
            iState := MB1_STATE#DEACTIVATE_F3_SECOND;
        END_IF;

    MB1_STATE#DEACTIVATE_F3_SECOND:
        udtExample.udtMB_TCP_FC3.xActivate := FALSE;
        iState := MB1_STATE#WAITING_FOR_INACTIVE_SECOND;

    MB1_STATE#WAITING_FOR_INACTIVE_SECOND:
        IF udtExample.udtMB_TCP_FC3.xActive = FALSE THEN
            iState := MB1_STATE#FINISH_OR_RESTART;
        END_IF;

    MB1_STATE#FINISH_OR_RESTART:
        IF (xRestartIfFinished = TRUE) THEN
            udtExample.uiRestartIfFinished := udtExample.uiRestartIfFinished + UINT#1;
            iState := MB1_STATE#CLIENT_INITIALISATION;
        END_IF;
        IF (xStart = FALSE) THEN
            iState := MB1_STATE#FINISH_WAITING_FOR_INACTIVE;
        END_IF;

    MB1_STATE#FINISH_DEACTIVATE_CLIENT:
        udtExample.udtClient.xActivate := FALSE;
        iState := MB1_STATE#FINISH_WAITING_FOR_INACTIVE;

    MB1_STATE#FINISH_WAITING_FOR_INACTIVE:
        IF (
            udtExample.udtMB_TCP_FC3.xActive = FALSE
        ) THEN
            iState := MB1_STATE#WAITING_FOR_START;
        END_IF;
END_CASE;