ECATReadData

 Function A function calculates a result according to the current value of its inputs. A function has no internal data and is not linked to declared instances. - Reads cyclic parameter (byte offset format).

Inputs

Input	Data Type	Range	Unit	Default	Description
Offset	UINT	0 to 1500	Bytes	No default	Offset in bytes from the beginning of the frame. The maximum size of an Ethernet Ethernet is a large, diverse family of frame-based computer networking technologies that operate at many speeds for local area networks (LANs) frame is 1500. The Offset value required to access may change when:    The firmware for any device on the EtherCAT ***EtherCAT 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 network is updated or    Whenever the EtherCAT network topology changes. When performing an update of a network device or changing the network topology, export the ENI file and check the Offset value needed to access the desired information.
Nbytes	SINT	1, 2, or 4	Bytes	No default	Number of bytes to read.
Direction	BOOL	0, 1	N/A	No default	Direction of the frame. TRUE = output image. FALSE = input image.

Outputs

Output	Data Type	Range	Unit	Description
Value	DINT	No range	N/A	Value of the EtherCAT frame.

Remarks

• 
  

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

• 
  
• 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 2147483647 (The sign bit represents the most significant bit in the data word).

• Allows a direct access to the memory EtherCAT Process Image of the EtherCAT frame which is sent or received when you need to debug the application.
• 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, this function is used for more than just debug.
  • It is used to get the status of the module (e.g., Stepper I/O slice) in the case the project is based on an external XML "Extensible Markup Language " XML is a general-purpose markup language. It is classified as an extensible language because it allows its users to define their own tags file because it contains unsupported EtherCAT device.
  • See Add an Unsupported EtherCAT Device for more information.

FBD Language Example

FFLD Language Example

IL Language Example

Not available.

ST Language Example

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

See Also

ECATWriteData