FP_NTP_SYNCHRONIZE

Request time synchronization from NTP server

This FP instruction sends a request to the NTP server to synchronize the time.

Input

nNumberOfRetries (WORD, INT, UINT)

Number of retries of requesting the time synchronization

Values: 0–20

nRetryInterval (WORD, INT, UINT)

Time synchronization interval

Values: 16–600

Output

nResult (WORD, INT, UINT): Execution result code

16#FFFF	In progress
16#0	Normal completion
16#10	Double startup error	The instruction requesting the time synchronization is being executed. NOTE The double startup error does not occur when the instruction is executed with the number of retries being set to 0 to cancel the time synchronization request instruction.
16#11	SNTP server address setting error	ET-LAN setting, SNTP server address setting = "0.0.0.0"
16#12	Disconnection error	Ethernet is disconnected.
16#13	Ethernet initialization active error	No IP address has been assigned to the Ethernet unit sending the request. (`sys_bIsEthernetIPAddressAssigned` is FALSE)
16#14	Number of retries setting error	The specified number of retries is out of range.
16#15	Retry interval setting error	The specified retry interval is out of range.
16#20	Response timeout error	The response time of processing the time synchronization request exceeds the predefined time. NOTE This error also occurs when an NTP IP address is not resolved.
16#30	Ethernet task response timeout	This error occurs when no response is returned from the Ethernet task.

Remarks

This instruction is not available in interrupt programs.
If a time synchronization timeout is foreseeable, set nNumberOfRetries to a higher value.
For cancelling further attempts to synchronize the time, set nNumberOfRetries to 0. In this case, the execution result code is not stored in nResult.
The timeout period for one time synchronization attempt is fixed at 3 seconds.
When multiple time synchronization attempts are specified, a new request starts after the timeout period elapses (3 seconds) plus the processing interval (specified by nRetryInterval).
The total timeout period (seconds) for time synchronization is obtained with the following formula: nRetryInterval x 3 + (nRetryInterval x (nNumberOfRetries-1)). (Here, nNumberOfRetries is larger than 0.)

Error flags

sys_bIsOperationErrorHold (turns to TRUE and remains TRUE)

if the area specified using the index modifier exceeds the limit.
if the instruction is executed in an interrupt program

sys_bIsOperationErrorNonHold (turns to TRUE for one scan)

if the area specified using the index modifier exceeds the limit.
if the instruction is executed in an interrupt program

Example

POU header

All input and output variables used for programming this function have been declared in the POU header.The same POU header is used for all programming languages.

	VAR
		bRequestSynchronization: BOOL:=FALSE;
		iNumberOfRetries: INT:=3;
		iRetryInterval: INT:=20;
		wResult: WORD:=0;
		bEnable: BOOL:=FALSE;
			END_VAR

LD body

When the system variable sys_bIsEthernetInitializing is FALSE and the variable bEnable is set to TRUE, the function is carried out.

BODY
    WORKSPACE
        NETWORK_LIST_TYPE := NWTYPELD ;
    END_WORKSPACE
    NET_WORK
        NETWORK_TYPE := NWTYPELD ;
        NETWORK_LABEL :=  ;
        NETWORK_TITLE :=  ;
        NETWORK_HEIGHT := 5 ;
        NETWORK_BODY
B(B_CONTACT,,sys_bIsEthernetInitializing,6,1,8,3,N);
B(B_CONTACT,,bEnable,15,1,17,3,);
B(B_F,FP_NTP_SYNCHRONIZE!,,22,0,35,5,,?DEN?DnNumberOfRetries?DnRetryInterval?AENO?AnResult);
B(B_VARIN,,iNumberOfRetries,20,2,22,4,);
B(B_VAROUT,,wResult,35,2,37,4,);
B(B_VARIN,,iRetryInterval,20,3,22,5,);
L(1,0,1,5);
L(1,2,6,2);
L(8,2,15,2);
L(17,2,22,2);
        END_NETWORK_BODY
    END_NET_WORK
    NET_WORK
        NETWORK_TYPE := NWTYPELD ;
        NETWORK_LABEL :=  ;
        NETWORK_TITLE :=  ;
        NETWORK_HEIGHT := 5 ;
        NETWORK_BODY
L(1,0,1,5);
        END_NETWORK_BODY
    END_NET_WORK
    NET_WORK
        NETWORK_TYPE := NWTYPELD ;
        NETWORK_LABEL :=  ;
        NETWORK_TITLE :=  ;
        NETWORK_HEIGHT := 5 ;
        NETWORK_BODY
L(1,0,1,5);
        END_NETWORK_BODY
    END_NET_WORK
END_BODY

ST body

if NOT (sys_bIsEthernetInitializing) AND (bEnable) then
    FP_NTP_SYNCHRONIZE(nNumberOfRetries := iNumberOfRetries,
    nRetryInterval := iRetryInterval,
    nResult => wResult);
end_if;