Fix PropDescRead and add comments from spec

This commit is contained in:
nanosonde 2018-04-24 16:32:57 +02:00
parent 2a4473c5ff
commit daf1cabedf

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@ -6,12 +6,24 @@ void InterfaceObject::readPropertyDescription(uint8_t& propertyId, uint8_t& prop
uint8_t count = propertyCount();
PropertyDescription* desc = nullptr;
// from KNX spec. 03.03.07 Application Layer (page 56) - 3.4.3.3 A_PropertyDescription_Read-service
// [...] and the Property of the object shall be addressed with
// a property_id OR with a property_index.The property_index shall be used ONLY if the property_id is zero.
// [...]
// If the property_id in the A_PropertyDescription_Read - PDU is NOT zero, then the field property_index
// shall be IGNORED; the remote application process shall use the indicated property_id to access the Property
// description.The property_index in the A_PropertyDescription_Response - PDU shall in this case be :
// - the correct value of the Property index of the addressed Property, or
// - the value of the field property_index of the received A_PropertyDescription_Read - PDU.
// For new implementations the property_index shall contain the correct value of the addressed Property.
// If the remote application process has a problem, e.g.Interface Object or Property does not exist, then the
// max_nr_of_elem of the A_PropertyDescription_Response - PDU shall be zero.
if (propertyId != 0)
{
for (uint8_t i = 0; i < count; i++)
{
PropertyDescription d = descriptions[propertyIndex];
PropertyDescription d = descriptions[i];
if (d.Id != propertyId)
continue;
@ -22,6 +34,10 @@ void InterfaceObject::readPropertyDescription(uint8_t& propertyId, uint8_t& prop
}
else
{
// If the property_id in the A_PropertyDescription_Read - PDU is zero, the remote application process shall
// use the indicated property_index to access the Property description.The property_index in the
// A_PropertyDescription_Response - PDU shall be the value of the field property_index of the received
// A_PropertyDescription_Read - PDU
if (propertyIndex >= 0 && propertyIndex < count)
{
desc = &descriptions[propertyIndex];
@ -36,4 +52,8 @@ void InterfaceObject::readPropertyDescription(uint8_t& propertyId, uint8_t& prop
numberOfElements = desc->MaxElements;
access = desc->Access;
}
else
{
numberOfElements = 0;
}
}