Pdo Mapping - Bosch Rexroth ID 40 Manual

9.9.1

PDO mapping

Eight bytes can be transmitted in each PDO. Which bytes are sent or received is
determined by the PDO mapping.
PDO contents can be dynamically mapped both in OPERATIONAL and PRE-
OPERATIONAL status.
The data bytes in RPDOs are then only applied to the mapped objects by the SLK
when the value of the RPDO status object (see Chapter 9.9.5 "Receive PDO status
[objects 2040–2041]") is 0x00. Applying the data of an executed RPDO to the SLK
can be prevented with the PDO invalid value of 0x80.
The TPDO status object (see Chapter 9.9.4 "Transmit PDO status [objects 2030–
2033]") indicates the validity of the transmitted contents.
Both the TPDO and RPDO mappings are generally independent of one another,
however the following restrictions should be observed.
1. Not all available objects are permitted for PDO mapping. This property is set for
each object in the EDS file (see Chapter 9.18 "Electronic data sheet [EDS]").
2. If both objects from the SLK register area (e.g., actual link state) and objects
from the MDT user data area are mapped in a TPDO, changing the link state
executes the TPDO.
However, if no MDT is linked at this time, the MDT data cannot be read. This
TPDO is marked as invalid in the PDO status.
It is recommended to not map MDT data or registers to a PDO with SLK registers.
3. In each RPDO, the data sent from the application is entered in every mapped
object – even when only one of the values should be written.
An RPDO overwrites all mapped objects, so pay attention to sent values.
4. Objects not allowing write access have the RO (read only) attribute. They cannot
be mapped to RPDOs.
Read-only objects cannot be mapped to RPDOs.
The values contained in the following tables (object indexes) are default values
for the ID 40/SLK. They can be adapted to the needs of the application through
command-oriented data exchange.
The default mappings are arranged symmetrically, i.e., objects that can be read and
written (R/W objects) are mapped to the same subindexes in TPDO and RPDO.
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