Omron C200HW-CORT21-V1, Operation Manual

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Communication
Section 1-3
8
Max. PDOs
Each PDO is defined by two records:
•
Communication parameters
•
Mapping parameters
Both records are part of the Communication Profile Area and can both be
adjusted via SDO accesses (see section 1-3-2).
The maximum number of PDOs in a CANopen network is limited to 512
Transmit PDOs (TPDOs) and 512 Receive PDOs (RPDOs). The predefined
connection set (the default configuration) defines 4 TPDOs and 4 RPDOs per
device. Refer to section 1-3-5 for more details about the predefined
connection set.
1-3-1-1 Communication parameters
COB-ID
Transmission modes
Synchronous PDOs
Asynchronous PDOs
Communication cycle time
Window length
The communication parameters define the
COB-ID
(Communication Object
IDentifier) and the transmission type (synchronous / asynchronous) of a data
object. Refer to section 1-3-5 for more details about the communication
object identifier.
CANopen defines two transmission modes:
•
Synchronous transmission
•
Asynchronous transmission
Synchronous PDOs are transmitted within the synchronous window after the
Sync Object (see section 1-3-3-1). The priority of synchronous PDOs should
be higher than the priority of asynchronous PDOs.
The transmission of synchronous PDOs can be subdivided into cyclic and
acyclic transmission mode. For synchronous cyclic PDOs, the number of the
transmission type (1 to 240) indicates the number of Sync Objects between
two PDO transmissions. Acyclically transmitted synchronous PDOs are
triggered by an application specific event. The message will be transmitted
synchronously with the Sync Object, but not periodically.
Asynchronous PDOs, and SDOs, can be transmitted at any time with respect
to their priority. So they can also be transmitted within the synchronous
window.
The communication cycle time (time between two Sync Objects) and the
window length are both objects in the Communication Profile Area and are
freely configurable.