ReadNbrSlaves (FB)

FUNCTION_BLOCK ReadNbrSlaves EXTENDS CBM.ETrigA

Reads the number of connected slaves

Example:

PROGRAM PLC_PRG
VAR
   readnbr : ReadNbrSlaves;
   xRead : BOOL;
   wNbrSlaves : WORD;
END_VAR

IF xRead THEN
   readnbr.usiCom := DWORD_TO_USINT(Ethercat_Master.InstanceNumber);
   readnbr(xExecute := TRUE, udiTimeOut := 1000);
   IF readnbr.xDone THEN
      xRead := FALSE;
      wNbrSlaves := readnbr.wNumberSlaves;
      readnbr(xExecute := FALSE);
    END_IF
 END_IF

InOut:

Scope	Name	Type	Initial	Comment	Inherited from
Input	xExecute	BOOL		Rising edge: Action starts Falling edge: Resets outputs If a falling edge occurs before the function block has completed its action, the outputs operate in the usual manner and are only reset if either the action is completed or in the event of an error. In this case, the corresponding output values (xDone, xError, iError) are present at the outputs for exactly one cycle.	ETrigA
	xAbort	BOOL		TRUE: Action is stopped immediately and all outputs are reset to their initial values.	ETrigA
Output	xDone	BOOL		TRUE: Action successfully completed	ETrigA
	xBusy	BOOL		TRUE: Function block active	ETrigA
	xError	BOOL		TRUE: Error occurred, function block aborts action FALSE: No error	ETrigA
	xAborted	BOOL		TRUE : Action aborted by user	ETrigA
Input	usiCom	USINT	1	index of master 1: first Ethercat master
	udiTimeOut	UDINT		Timeout for operation in ms
Output	wNumberSlaves	WORD		number of slaves currently available