EI_API_CIP_setClassAttrFunc()

uint32_t EI_API_CIP_setClassAttrFunc	(	T *	pCipNode_p,
		uint16_t	classId_p,
		EI_API_CIP_SAttr_t *	pAttr_p
	)

Register a callback function to a specific CIP attribute.

This function may be used to register a callback function for a CIP class attribute. This callback will be executed every time the registered access rules (get or set) are triggered.

Remarks

Registration of a callback is required for each attribute you are interested.

Parameters

[in]	pCipNode_p	Pointer to the CIP node.
[in]	classId_p	Class identifier.
[in]	pAttr_p	Pointer to struct of attribute parameters.

Returns

EI_API_CIP_EError_t as uint32_t value.

Return values

EI_API_CIP_eERR_OK	Success.
EI_API_CIP_eERR_NODE_INVALID	CIP node is invalid, possibly EI_API_CIP_NODE_new() was not called.
EI_API_CIP_eERR_CLASS_DOES_NOT_EXIST	Class does not exist in CIP node dictionary.
EI_API_CIP_eERR_ATTRIBUTE_INVALID	Attribute is invalid, possibly NULL pointer.
EI_API_CIP_eERR_ATTRIBUTE_DOES_NOT_EXIST	Attribute does not exist in class or instance.
EI_API_CIP_eERR_ATTRIBUTE_INVALID_CALLBACK	Callback can not be registered (invalid function pointer).
EI_API_CIP_eERR_ATTRIBUTE_UNKNOWN_STATE	Unknown state during attribute operation reached.

Example

uint32_t cbCountUpUsint(EI_API_CIP_NODE_T* pCipNode, uint16_t classId, uint16_t instanceId, uint16_t attrId, uint16_t* len, void* pvValue)
{
  uint32_t retVal = EI_API_eERR_CB_INVALID_VALUE;
  // Elementary data type USINT
  ei_api_cip_edt_usint attrUsintValue;
  uint32_t  errCode;
 
  // Get current attribute value into attrUsintValue
 
  errCode = EI_API_CIP_getAttr_usint(pCipNode, classId, instanceId, attrId, &attrUsintValue);
  if(EI_API_CIP_eERR_OK == errCode)
  {
      // Increment value
      ++attrUsintValue;
      // set the value back into the attribute
      errCode = EI_API_CIP_setAttr_usint(pCipNode, classId, instanceId, attrId, attrUsintValue);
      if(EI_API_CIP_eERR_OK == errCode)
      {
         // prepare the return values for the callback
         *(ei_api_cip_edt_usint *)pvValue = attrUsintValue;
         *len = sizeof(ei_api_cip_edt_usint);
         retVal = EI_API_eERR_CB_NO_ERROR;
      }
   }
  return retVal;
}
 
uint32_t registerCallback(EI_API_CIP_NODE_T *pCipNode_p)
{
    uint32_t errCode;
 
    uint16_t classId = 0x64;
 
    // Initialize structure to zero/null
    EI_API_CIP_SAttr_t attr = { 0 };
    EI_API_CIP_CBGetAttr ptr_cb = cbCountUpUsint;
 
    attr.id = 0x66;
    attr.accessRule = EI_API_CIP_eAR_GET;
    attr.get_callback = ptr_cb;
    attr.set_callback = NULL;
 
    errCode = EI_API_CIP_setClassAttrFunc(pCipNode_p, classId, &attr);
 
    return(errCode);
}

See also

EI_API_CIP_CBGetAttr EI_API_CIP_CBSetAttr EI_API_CIP_addClassAttr EI_API_CIP_getClassAttr EI_API_CIP_setClassAttr EI_API_CIP_SAttr EI_API_CIP_EError_t