Dynamic PDO and objectlist

[arbite]

Hi,

I've been experimenting with the dynamic PDO functionality of SOES. In the slave_objectlist.c we define the available PDO entries, eg:

const _objd SDO1C12[] = 
{
  {0x00, DTYPE_UNSIGNED8, 8, ATYPE_RWpre, acName1C12_00, 8, &Obj.SM1C12.maxsub},
  {0x01, DTYPE_UNSIGNED16, 16, ATYPE_RWpre, acName1C12_01, 0x1600, &Obj.SM1C12.value[0]},
  {0x02, DTYPE_UNSIGNED16, 16, ATYPE_RWpre, acName1C12_02, 0x1601, &Obj.SM1C12.value[1]},
  {0x03, DTYPE_UNSIGNED16, 16, ATYPE_RWpre, acName1C12_03, 0x0000, &Obj.SM1C12.value[2]},
  {0x04, DTYPE_UNSIGNED16, 16, ATYPE_RWpre, acName1C12_04, 0x0000, &Obj.SM1C12.value[3]},
  {0x05, DTYPE_UNSIGNED16, 16, ATYPE_RWpre, acName1C12_05, 0x0000, &Obj.SM1C12.value[4]},
  {0x06, DTYPE_UNSIGNED16, 16, ATYPE_RWpre, acName1C12_06, 0x0000, &Obj.SM1C12.value[5]},
  {0x07, DTYPE_UNSIGNED16, 16, ATYPE_RWpre, acName1C12_07, 0x0000, &Obj.SM1C12.value[6]},
  {0x08, DTYPE_UNSIGNED16, 16, ATYPE_RWpre, acName1C12_08, 0x0000, &Obj.SM1C12.value[7]},
};

If I wanted to have a huge dynamic PDO, say 256 entries, is it necessary to build a huge const _objd for each entry? Is it possible to generate this information programmatically, eg through pre_object_download_hook or pre_object_upload_hook?

A second question: Is it possible to to have dynamic PDOs of differing data types, that is assigned by the master? An example might be: One startup configuration, SOEM requests DTYPE_UNSIGNED32, DTYPE_UNSIGNED8, DTYPE_UNSIGNED16 then on the next startup SOEM might request DTYPE_UNSIGNED8, DTYPE_UNSIGNED8. I guess I'm asking if the dynamic PDOs must be pre-defined in the objectlist as the same datatypes. I hope this makes sense!

Thank you.

[nakarlsson]

If I wanted to have a huge dynamic PDO, say 256 entries, is it necessary to build a huge const _objd for each entry?

I guess it is possible.

A second question: Is it possible to have dynamic PDOs of differing data types, that is assigned by the master?

Yes,

ex &Obj.SM1C12.value[0] could be assigned to PDOs of different type on start-up.

OR

ex PDO config

const _objd SDO1A01[] = { {0x00, DTYPE_UNSIGNED8, 8, ATYPE_RWpre, acName1A01_00, 8, &Obj.PDO1A01.maxsub}, {0x01, DTYPE_UNSIGNED32, 32, ATYPE_RWpre, acName1A01_01, 0x00000000, &Obj.PDO1A01.value[0]},

were &Obj.PDO1A01.value[0] can be programmed with PDO index, subindex, length.

[arbite]

I guess it is possible.

Hmm, maybe my question was not very good!

My use case is - I would like to use a large dynamic PDO as an array, but I am reasonably memory constrained. Creating a huge const _objd that will only point to elements in an array is not a very good use of memory for me. To put it more simply, I do not want to create a huge const _objd for the large PDO. I was originally asking if I could generate those sections that point to the large PDO array at run time, by hooking via eg pre_object_upload_hook or pre_object_download_hook?

Or, could I just omit that section of the objd?

Thanks again

[nakarlsson]

So you want a single PDO of type ARRAY?

[arbite]

Yes I think that would be right. Would this be using something like DTYPE_ARRAY_OF_INT for example, and setting the bitlength to anything (0 most likely).

Thank you

[nakarlsson]

@arbite , can we close this issue?

[arbite]

Hi, yes that is fine. Thanks