User Manual CANopen/EtherCAT
34
6.4 PDO transmission types
In connection with the PDO transfer, various transmission types are defined in CANopen
profile DS301. The transmission type and event control can be set separately for all sup
-
ported RXPDOs and TXPDOs. The drive controller supports the following transmission
types:
Cyclic Synchronous Types No. 1-F0 h
Meaning: The difference between this and the acyclic synchronous transmission type is
that RXPDOs are only evaluated after receipt of 1-F0 h Sync objects and TxPDOs are only
transmitted every 1-F0 h Sync objects.
Asynchronous Types No. FE h and FF h
Meaning: RxPDOs are evaluated immediately on receipt; TxPDOs are transmitted by a de-
vice-specific event. The Sync object is irrelevant to this mode of transfer. Special feature
type FF h:
In this case the event is defined in the associated device profile.
Note: The desired transmission types are set by way of the corresponding
CANopen objects 1400h for RxPDOs and 1800h for TxPDOs.
6.5 Event-controlled TxPDO transmission
Note: Event control is only active when the relevant “transmission type“
is set to asynchronous (FEh or FFh).
Functions of event control:
Any bit changes within the TxPDO can serve as an event for the sending of a TxPDO.
Thus only the mapped contents of this TXPDO are relevant as an event for the sending
of a TxPDO. Accordingly it is not possible to send a TxPDO dependent on the changes to
the content of another TxPDO.
Example:
The status word 6041h is mapped in TxPDO1. TxPDO2 contains the current actual posi
-
tion. A change to the status word in TxPDO1 can therefore not be used as an event for
the sending of the TxPDO2. If this is required, however, the status word 6041h can also
be mapped in TxPDO2.
Selecting the events:
In ServoOne every bit (or a change to it) in a TxPDO can be defined as an event. By de-
fault all bits (max. 64bit = 8byte) are monitored for changes and are evaluated as events.
Individual bits can be displayed via screens, however, and therefore are no longer used
for event generation.
There are screens defined in field parameter 2007 enabling the display of individual bits
of TxPDOs. Subindexes are respectively relevant for a TxPDO. Each subindex is responsib-
le for 32 bits of the TxPDO. The structure is thus as follows:
To Next Page
Loading...
