EtherCAT Editor: PDO Mapping Tab

To access this window: In the EtherCAT Editor, in the EtherCAT Explorer pane, click a SubDevice in the list, then click the PDO Mapping tab.

Use the PDO Mapping tab to define the Process Data Object (PDO) data that is transmitted between the RMC MainDevice and the selected SubDevice.

The PDO Mapping box lists all the PDOs provided by the SubDevice. The PDOs may or may not be editable. Only the data in PDOs with a check mark in the Assign column will be used in the EtherCAT communication.

PDO Mapping Box

When the PDO button on the top right is selected, the PDO Mapping box is displayed.

The columns in the PDO Mapping box are:

Assigned
If this box is checked, the data in that PDO will be communicated. For some SubDevices, multiple PDOs in each direction can be checked, whereas other prevent this. Yet others allow multiple PDOs to be selected but will only use the first one. Consult the SubDevice documentation for details.
Name and Direction
These specify the direction:
Input (IN): Data coming into the RMC. This is also called a SubDevice Transmit PDO.
Output (OUT): Data going out from the RMC. This is also called a SubDevice Receive PDO.
Index
This is the address of the PDO Mapping. Any changes you make in the specified PDO will be written to that index.

Editing the PDO Mapping

The PDOs may or may not be editable. If the SubDevice has a Modules tab, the PDO Mapping will likely be set by the Modules selection.

View PDOs

Click the arrow button to view the contents of a PDO.

Add, Remove and Re-order PDOs

It is often unnecessary to add or remove PDO Mappings (it is more common to add or remove data objects within a PDO as described below). If you wish to do so, use the Add, Delete, Edit, Up, and Down buttons below the PDO Mapping box.

Add or Remove Data in a PDO

To change the data objects in a PDO, such as add or remove objects:

Select a PDO in the list, then click the Edit button below the PDO Mapping box. The Edit PDO dialog opens.
If the PDO is editable, in the Entries box, select an item and use the Add, Delete, Edit, Up, and Down buttons. When adding or editing items you can edit the Name field to provide more detail about the data item.
In SubDevices with many PDO Mappings, you may wish to change the Name to reflect the purpose of that particular PDO Mapping.

Some SubDevices only allow changes to certain PDO Mappings. Consult the SubDevice documentation to see if the PDO Mapping is configurable.

FMMU and SM Boxes

When the FMMU/SM button on the top right is selected, the FMMU and SM boxes are displayed.

The FMMU (Fieldbus Management Unit) and SM (Sync Managers) boxes list advanced information. Refer to the EtherCAT Trade Group (ETG) documentation for more information.