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The master or network manager can request the sensor via NMT messages to
change the state accordingly.
9.1.4 Use of 32 bit data types
CANopen defines data types with a maximum size of 64 bits (8 bytes). By means
of the data type, the user data of ID tags is transmitted efficiently via the
interface. The data type is also used for the default setting of the device and the
file.
However, some controllers can only process data types with a maximum width of
32 bits (4 bytes). In order to support all types of controllers, the device offers
alternative data objects whose data types are restricted to max. 32 bits. These
data objects are marked by the addition “32 bits” in these instructions. Additionally,
an EDS file is supplied for use of the data types that is read by the controller
software.
By default, the device uses 64-bit data types (e.g. for the preconfigured
The setting must be adapted to the use of 32-bit data types. The setting can be
changed via the controller software, by reading the corresponding EDS file.
9.1.5 Communication types of the process data object (PDO)
can be checked at any time by transmitting a remote transmission
request telegram (RTR). Otherwise the TPDOs are sent automatically as soon as
their value changes (event-driven).
As an option, the CANOpen service “
” can be used (see CiA 301, 7.2.5
Synchronization object (SYNC)). For the synchronised transmission CANopen
provides the SYNC object at which the TPDOs are transmitted after every "nth"
reception of a SYNC telegram.
A total of 64 TPDOs and 64
is available; on delivery only the first 4 of
each are active. If the configuration of the CANopen network allows it, the
remaining process data objects can also be activated.
In the standard settings, the process data is assigned to the linear address range
of the ID tag. The TPDO1 maps e.g. the first 8 bytes of the user data memory of
the ID tag.
Reading of the memory and transmission of the data via TPDO is effected
automatically as soon as a new ID tag is detected.
