Lenze 931K - Manual (Page 36)

CANopen communication
Process data transfer (PDO transfer)
Description of the objects
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36 KHB 13.0002−EN 4.1
Objects to be transferred (first_mapped_object ... fourth_mapped_object)
For every object to be contained in the PDO, the drive controller must know the
corresponding index, subindex and length. The specified length must be identical to the
length specified in the object dictionary. It is not possible to map parts of an object.
The mapping information has the following format:
Index Subindex Length
16 bits 8 bits 8 bits
ƒ Index: Main index of the object to be mapped (hex)
ƒ Subindex: Subindex of the object to be mapped (hex)
ƒ Length: Length of the object (hex)
The following mandatory procedure serves to simplify the mapping:
1. The number of the mapped objects is set to 0.
2. The first_mapped_object ... fourth_mapped_object parameters can be written (the
total length of all objects is not relevant at this time).
3. The number of the mapped objects is set to a value between 1 ... 4. The total length
of these objects must not exceed 64 bits.
Masking (transmit_mask_high and transmit_mask_low)
If "change" is selected for the transmission_type, the TPDO is always sent if at least 1 bit
of the TPDO has changed.
However, very often it is necessary to send the TPDO only if a certain bit has changed. For
this purpose, the TPDO can be provided with a mask. Only those bits of the TPDO are
evaluated which are set to "1" in the mask.
In the default setting all bits of the masks are set.