CanApiTimeTriggeredMsg (FB)

Epec Programming and Libraries Manual

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Supported platforms: CODESYS 3.5 SAFETY

CanApiTimeTriggeredMsg (FB)

Description

This function block (FB) is used to define time triggered CAN message. The maximum number of messages is 10.

Minimum time interval for sending is 1 ms, but it is recommended to use intervals > 10 ms.

Message is initialized with InitCobId method and sending is started by setting i_Enable to TRUE.

Function block must be called at least every 100 ms, otherwise sending is stopped. New data is updated

by setting new values to i_Dlc and i_Data inputs and calling UpdateData method.

Limitations

Maximum number of the send messages is 10
Accuracy of the time is +-2 ms
Minimum time interval for sending is 1 ms, but it is recommended to use intervals > 10 ms.
Used CAN channel must be initialized before initializing the time triggered messages.
Function block instance must be called at least every 100 ms, otherwise message sending is stopped

InitCobId (METHOD)

This method initializes time triggered CAN message.

Inputs

Input variable name	Data type	Description
i_CanChannel	BYTE	Used CAN channel
i_CobId	DWORD	Used COB-ID
i_TimeInterval	TIME	Time interval for sending

Return value

Data type	Description
EPEC_SYSTEM.SYSTEM_ERROR_CODES	FW error code.

RemoveCobId (METHOD)

This method removes time triggered CAN message.

The method has no inputs.

Return value

Data type	Description
EPEC_SYSTEM.SYSTEM_ERROR_CODES	FW error code.

UpdateData (METHOD)

This method updates i_Dlc and i_Data values of time triggered CAN message.

The method has no inputs.

Return value

Data type	Description
EPEC_SYSTEM.SYSTEM_ERROR_CODES	FW error code.

Normal operation

Inputs

Input variable name	Data type	Description
i_Enable	BOOL	Enable operation
i_Dlc	BYTE	Message length
i_Data	ARRAY [0..7] OF BYTE	Message data

Outputs

Output variable name	Data type	Description
o_UsedCanChannel	BYTE	Configured channel (= input for method InitCobId).
o_InitializedCobId	DWORD	Configured COB-ID (= input for method InitCobId).
o_UsedTimeInterval	TIME	Configured time interval (= input for method InitCobId).
o_Error	EPEC_SYSTEM.SYSTEM_ERROR_CODES	FW error code.

Example code

Definitions:

canChannel:EPEC_CANL2.Channel; (*not required with MT code template*)

timeTrgSending:EPEC_HWD.CanApiTimeTriggeredMsg;

Init:
(If using MultiTool Creator, CAN channel init is already included in code template) canChannel.InitCAN(0,250,0); (* Init channel 0 for 250 kbit/s) timeTrgSending.i_Enable := FALSE; timeTrgSending.i_Dlc := 8; timeTrgSending.InitCobId(0,16#100,T#10MS); ( Init message, 10ms interval *)

Code:

(*Update message data*)

timeTrgSending.i_Data[0] : = 1;

timeTrgSending.i_Data[1] : = 2;

timeTrgSending.i_Data[2] : = 3;

timeTrgSending.i_Data[3] : = 4;

timeTrgSending.i_Data[4] : = 5;

timeTrgSending.i_Data[5] : = 6;

timeTrgSending.i_Data[6] : = 7;

timeTrgSending.i_Data[7] : = 8;

(*Update data for message handler*)

timeTrgSending.UpdateData();

(*Call handler periodically*)

timeTrgSending(i_Enable := TRUE);