ECATReadData

• 
  

• This is a low level function and it should only be used carefully by advanced users.

Description

This function allows a direct access to the memory image of the EtherCATEtherCAT is an open, high-performance Ethernet-based fieldbus system. The development goal of EtherCAT was to apply Ethernet to automation applications which require short data update times (also called cycle times) with low communication jitter (for synchronization purposes) and low hardware costs frame which is sent or received when you need to debug your application. You access the EtherCAT image element by giving the offset in the image and the size of the element.

If you have a device other than the drive, ECATReadData is used for more than just debug. It is used to get the status of the module (e.g. Stepper I/O slice).

Arguments

Input

Offset	Description	Offset in bytes from the beginning of the frame The Offset value required to access may change when the firmware for any device on the EtherCAT network is updated or whenever the EtherCAT network topology changes. When performing an update of a network device or changing the network topology, one should export the ENI file and check the Offset value needed to access the desired information.
	Data type	UINT
	Range	0-size of frame (maximum size of an EthernetEthernet is a large, diverse family of frame-based computer networking technologies that operate at many speeds for local area networks (LANs) frame is 1500)
	Unit	bytes
	Default	—
Nbytes	Description	Number of bytes to read
	Data type	SINT
	Range	1, 2 or 4
	Unit	bytes
	Default	—
Direction	Description	Direction of the frame (true = output image, false = input image).
	Data type	BOOL
	Range	0, 1
	Unit	N/A
	Default	—

• 
  
• The valid ranges for the Value parameter are:
  For 1 byte: 0 to 255
  For 2 bytes: 0 to 65535
  For 4 bytes: - 2147483648 to 2147483648 (The sign bit represents the most significant bit in the data word)

Output

Value	Description	Value of the EtherCAT frame
	Data type	DINT
	Unit	N/A

Related Functions

ECATGetObjVal

Example

Structured Text

// Read 4 bytes starting at offset 26 of the output image   Position := ECATReadData(26, 4, true);

FBD

FFLD

 [Top]