Siemens MICROMASTER 420 Operating Instructions Manual page 48

Data transfer using CANopen
The Transmission Type (operating mode) specifies the data transfer type and the
trigger initiation for a PDO. For synchronous Transmit PDOs, the Transmission
Type also defines the data transfer rate in the form of a factor. For a factor of 0, the
PDO is transferred after each SYNC object if an additional event has occurred (a
value has changed). For a factor of 1, the PDO is transferred after every SYNC
object. For a factor n (n = 1 - 240), the PDO is sent after every n
Non-synchronous PDOs are sent independently of the SYNC object. Data of a
synchronous Receive PDO, that is received after a SYNC object, is processed by
the application after the next received SYNC object - independently of the value of
the factor for the Transmission Type. The data of an asynchronous PDO are
always directly transferred to the application.
For receive PDOs, the MICROMASTER 420/430/440 only makes a differentiation
between synchronous and non-synchronous PDOs. The factor is not saved in the
MICROMASTER. This means that after power on, the MICROMASTER only
displays in the communication objects as to whether it received the PDO
synchronously or non-synchronously. The Power-On value of CANopen objects,
that can define the data transfer type of the PDOs, can, under certain
circumstances, deviate from the true values of the objects in the drive inverter. This
is the reason that we urgently recommend that these objects are not saved using a
"SAVE" command via object 0x1010. In fact, after every Power-On command they
should be explicitly re-defined by CAN in order to avoid an incorrect function.
SYNC object
Cicle time
Synchronous Window Length
Act. value
Setpoints
Synchronous PDOs
Fig. 3-13 Data transfer types
Fault: PDO data transfer type:
If these objects are at 255, and were saved with "Save", then they can no longer be
set back to a synchronous data transfer type. Or, the CAN display remains at the
value 255, even if the inverter is reset to 0 using the commissioning (start-up) tool
and this is also displayed.
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SYNC object
Act. value
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Synchronous PDOs
Cicle time
Synchronous Window Length
Setpoints
Synchronous PDOs
CANopen Option Module
Issue 01/05
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SYNC signal.
SYNC object
time
Operating Instructions
6SE6400-5BC00-0BP0