RtecatAoeReadCommand

RtecatAoeReadCommand reads data from a SubDevice through AoE (Automation Device Specification over EtherCAT).

Syntax

Copy

RTECAT_COMMAND_STATUS RtecatAoeReadCommand(
  [in]    RTECAT_HANDLE SubDevice,
  [in]    WORD Port,
  [in]    ULONG IndexGroup,
  [in]    ULONG IndexOffset,
  [out]   BYTE* pValue,
  [in]    ULONG Length
);

Parameters

[in] SubDevice

A handle to a SubDevice. To retrieve the corresponding handle, use RtecatOpenSubDeviceByIndex, RtecatOpenSubDeviceByStationAddress, or RtecatOpenSubDeviceByExplicitId.

[in] Port

The SubDevice port.

[in] IndexGroup

An index group of an object.

[in] IndexOffset

The offset of an object in an index group.

[out] pValue

A pointer to the buffer that stores the data from the SubDevice.

[in] Length

The length, in bytes, of the value to read. The valid range is 1-512.

Return Values

The function returns an RTECAT_COMMAND_STATUS structure. If an error occurs, field State of the structure is set to ecatCommandError and the error code is stored in field ErrorId (see RTECAT_ERROR for error values). If the function succeeds, ErrorId is set to ecatErrNoError (which is represented by the value 0). If the function fails, it stores a different error value.

Possible return values:

Return value	Meaning
ecatErrNoError	The function succeeded.
ecatErrNullParameter	Parameter pValue is NULL.
ecatErrWrongParameter	One of the following conditions occurred: Parameter SubDevice is invalid. The value of parameter Length is zero (0) or greater than 512.
ecatErrMainDeviceNotReady	The MainDevice is not ready.
ecatErrFeatureUnavailable	The SubDevice doesn't support AoE.

Remarks

RtecatAoeReadCommand is an asynchronous function that takes time to complete. It allows for background execution and requires you to check its status by calling RtecatGetCommandStatus or wait for it to complete by calling RtecatWaitForCommand.

Requirements

Minimum supported version	Header	Library
wRTOS 1.0 SDK	RtecatApi.h	RtecatApi_W64.lib (Windows), RtecatApi.lib (RTSS)