This view is used to configure the Process Data Objects (PDO).
PDOs are messages send without confirmation used for real time information transfer. PDOs are mapped to a single CAN frame and can contain multiple object dictionary entries with a maximum of 8 bytes of data. Each PDO has an identifier and is transmitted by only one node in the network, however it could be received by more than one node. PDOs must be configured previous to using them.
There are two types of PDO messages: Transmit PDO (TPDO) and Receive PDO (RPDO). It is possible to configure up to 4 TPDO and 4 RPDO.
Steps to configure a PDO
1-Select the desired PDO from the drop down list at the top of the window.
2-From the left table of mappable objects, drag and drop the ones desired to the right table.
3-A colored bar helps the user to see the mapping capacity of the current PDO. The size is measured in bytes.
4-Define PDO parameters:
In CANopen messages the identifier part of the arbitration field is known as Communication Object Identifier (COB-ID). It is divided into a 4-bit part function code and a 7-bit node-ID as depicted:
Type of transmission for the PDO. Options are:
|Event mode||Trigger for the transmission: Value changed, timer or both|
|Min refresh rate (ms)||Minimum refresh rate in case of Event driven transmission type with event mode equal to value changed. If no changes occurs after the Min refresh rate time, the PDO will be sent.|
|Timer duration (ms)||Timer duration for the Event mode = timer|
Refer to CANopen protocol documentation for further information on PDO