How to write PDO mapping config

[tom9672]

We can use the default pdo mapping by this:

class OutputPdo(ctypes.Structure):
    _pack_ = 1
    _fields_ =[
        ('Control_Word',ctypes.c_uint16),
        ('Mode_Operation',ctypes.c_int8),
        ('Target_Position',ctypes.c_int32),
        ('Touch_probe_function',ctypes.c_uint16),
        ('physical_outputs',ctypes.c_uint32),
        ('bit_mask',ctypes.c_uint32)
    ]   

output_data = OutputPdo()

but how can we set the pdo mapping (write pdo mapping to device)?

I guess, use sdo to write to the address x1A00, x1600? but the pdos are lists of addresses, how to set the PDOS？ so that i can select the pdos that i need instead of using the default.

[rako233]

Take a look into CanOpen specs, how to to this. It doesn't work with all slaves though, because they can't be changed

[bnjmnp]

I think in CANOpen it is not the best direction to look into, there it is a bit different.

For each EtherCAT slave device, PDO change might be implement in another way.

• (fixed PDO mapping:) For some device changing PDO mapping is not possible at all, this is the case when 0x1C12/0x1C13 and 0x1600-0x17FF/0x1A00-0x1BFF are read-only .
• (Selectable PDO mapping:) Others allow PDO change by allowing write access to 0x1C12/0x1C13 where only 0x1600-0x17FF/0x1A00-0x1BFF is read only. This is maybe the most common implementation. Examples are shown in the elxxxx_setup functions of the minimal_example.py and basic_example
• (Configurable PDO mapping:) Some device allwo complete PDO change by allowing write access to both 0x1C12/0x1C13 and 0x1600-0x17FF/0x1A00-0x1BFF.
• (?:) Devices that are similar to CANopen allow write access to only 0x1600/0x1A00, where 0x1C12/0x1C13 are read only or 0x1C12/0x1C13 are only allowed to map 0x1600/0x1A00 or nothing at all.