SALARM (FB)

FUNCTION_BLOCK SALARM

A Field Device can generate alarms to its associated Host Controller to inform it e.g. about certain process events or other events to state there are some limitations of the capabilities of the Field Device for diagnostic reasons. The Host application may use the RALARM function block to receive these alarms.

The ID parameter identifies the slot of the Field Device the alarm is generated for. The ATYPE input shall contain the alarm type. The ASPEC input shall contain the alarm specifier. The LEN input contains the length in byte of the additional alarm information stored in the AINFO parameter.

The Variable given as AINFO parameter shall be at least of LEN byte.

If the alarm is transmitted successfully, the VALID output indicates that the alarm was received by the Host Controller.

If an error occurred, the ERROR output indicates an error and the STATUS output contains the error code.

Code-Example

PROGRAM SendAlarm
VAR
    sender : CommFB.SALARM;
    alarmPayload : ARRAY[0..3] OF BYTE := [0, 1, 2, 3];     // encoding for Profinet: USI (UInt16), ARRAY[0..n] OF BYTE;
    ID : DWORD := CommFB.Constants.INVALID_ID;
END_VAR

ID := CommFB.SUBSLOT_ID(EN := TRUE, ID := PN_Device.DeviceID, SLOT := 2, SUBSLOT := 1);
sender.ID := ID;
sender.ATYPE := ProfinetCommon.AlarmType.PROCESS;
sender.ASPEC := 0;      // 0 for process-alarm
sender.LEN := SIZEOF(alarmPayload);
sender.AINFO := ADR(alarmPayload);
sender();

IF(sender.DONE OR sender.ERROR) THEN
    sender(REQ := FALSE);
END_IF

InOut:

Scope	Name	Type	Comment
Input	REQ	BOOL	The function is invoked when the REQ input is equal to 1.
	ID	DWORD	Handle of the slot of the alarm source
	ATYPE	UINT	Type of the alarm
	ASPEC	UINT	Specifier of the alarm
	LEN	UINT	Length of AINFO data in bytes
	AINFO	POINTER TO BYTE	Additional alarm information
Output	DONE	BOOL	Indicates that the alarm was received by the Host Controller
	BUSY	BOOL	FB is busy
	ERROR	BOOL	Error detected
	STATUS	DWORD	Last detected status