EI_API_CIP_setInstanceAttrFunc()

uint32_t EI_API_CIP_setInstanceAttrFunc	(	T *	pCipNode_p,
		uint16_t	classId_p,
		uint16_t	instanceId_p,
		EI_API_CIP_SAttr_t *	pAttr_p
	)

Register a callback function to a specific CIP attribute.

This function can be used to register a callback function to a CIP attribute. The callback will be executed if the registers access rule (get or set) are triggered.

Remarks

You have to register the callback for every attribute you are interested.

Parameters

[in]	pCipNode_p	Pointer to the CIP node.
[in]	classId_p	Class identifier.
[in]	instanceId_p	Instance 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 exists in CIP node dictionary.
EI_API_CIP_eERR_INSTANCE_DOES_NOT_EXIST	Instance does not exist in CIP node dictionary.
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 = 0x0064;
    uint16_t instanceId = 0x0066;
 
    // Initialize structure to zero/null
    EI_API_CIP_SAttr_t attr = { 0 };
    EI_API_CIP_CBGetAttr ptr_cb = cbCountUpUsint;
 
    attr.id = 0x68;
    attr.accessRule = EI_API_CIP_eAR_GET;
    attr.get_callback = ptr_cb;
    attr.set_callback = NULL;
 
    errCode = EI_API_CIP_setInstanceAttrFunc(pCipNode_p, classId, instanceId, &attr);
 
    return(errCode);
}

See also

EI_API_CIP_CBGetAttr EI_API_CIP_addInstanceAttr EI_API_CIP_getInstanceAttr EI_API_CIP_setInstanceAttr EI_API_CIP_SAttr EI_API_CIP_EError_t