02.2004 Communication / CBC CANopen Communication Board
Siemens AG 6SE7087-6QX70 (Version AD)
SIMOVERT MASTERDRIVES Compendium Motion Control 8.5-29
8.5.2.3 Relation between PDO/PZD and SDO/PKW
In the CANopen profile, every object can be read or written with an
SDO task. This applies in the case of MASTERDRIVES only if the
correct interconnections have been made. The last two columns in the
table of objects specify the transmission options and the associated
parameters or connectors.
MASTERDRIVES recognizes two transmission modes in connection
with PROFIBUS, i.e. the PKW (parameter identifier value) task and
PZD (process data).
A PKW task can be used to read or write MASTERDRIVES
parameters. This type of task consists of a parameter number, a task
identifier and a value.
PZD such as setpoints and actual values are updated cyclically with
Profibus. Process data are 'wired' directly from the CB board to the
target parameter via a dual port RAM channel. For this reason, they do
not require addressing.
PZD values cannot be written by means of a PKW task nor are PZD
capable of accessing parameters.
A CANopen SDO task is directly comparable to a PKW task.
PDOs correspond to PZD in the PROFIBUS.
All objects can be transmitted per SDO with CANOpen.
Fixed setpoints are used as a means of writing process data in
MASTERDRIVES via an SDO task. The connectors of the fixed
setpoints must be wired to the corresponding setpoint parameters.
SDO tasks are sent via identifiers 600h + NodeID (Client>Server) and
580h + NodeID (Server>Client).
If you want to send a DSP 402 object as simply an SDO from the
CANopen master when it corresponds to a process data in
MASTERDRIVES and has not been mapped into a PDO, then it is not
transmitted as normal via the dual port RAM, but diverted via a fixed
setpoint. When the SDO is addressed via the parameter channel of the
CBC, the setpoint is set to the possibly re-normalized value which is
stored in the SDO (see table of objects, Parameters / Connectors
column).
The outgoing connector for the fixed setpoint must be "wired" up to the
MASTERDRIVES location to which the setpoint must be applied.
The object 60FFh target_velocity may only be transmitted as an SDO
via the bus. To do this, proceed as follows:
Find the fixed setpoint (U018) to which the SDO of the object writes in
the table of objects. Then take the connector (KK0418) belonging to the
fixed setpoint and connect it up to parameter P212 (Src Ctrl Setp).
All objects that cannot be transferred as PDOs according to the table
are MASTERDRIVES parameters that can only be transmitted as
SDOs.
SDO tasks
Example
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