ECATReadData

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 Function - 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 frame is 1500.


  • 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, 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

FALSE, TRUE

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 file because it contains unsupported EtherCAT device.
    • See Add an Unsupported EtherCAT Device.

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