ReadMemory (FB)¶

FUNCTION_BLOCK ReadMemory EXTENDS ETrigA

This function block is for reading the memory of EtherCAT Slaves.

Example:

Following example code reads the register 0x130 (current status)

PROGRAM PLC_PRG
VAR
   etcreadmemory : ReadMemory;
   wStatus : WORD;
   xRead : BOOL;
END_VAR
etcreadmemory(xExecute := xRead, usiCom:=1, wSlaveAddress := 1002,
     xAutoIncAdr := FALSE, xBroadcast := FALSE, uiMemOffset := 16#130,
     iSize := 2, pDest := ADR(wStatus), udiTimeout := 500);

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
Input	`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
	`wSlaveAddress`	`WORD`		address either auto increment address or physical address of device
	`xAutoIncAdr`	`BOOL`		flag that determines which way to use the given address
	`xBroadcast`	`BOOL`		flag if broadcast read should be used, if true then wSlaveAddress and bAutoIncAdr are not used
	`uiMemOffset`	`UINT`		offset of memory
	`iSize`	`INT`		bytes to read
	`pDest`	POINTER TO BYTE		buffer to store the data
	`udiTimeOut`	`UDINT`		Timeout for operation in ms
Output	`uiWorkingCounter`	`UINT`		working counter of received command

Methods:

ReadPacket

Structure:

ReadPacket (Method)