Tab: CANopen Safety Slave – SRDOs

The tab is used for displaying the SRDOs and the experts in addition to the definition of the safety-related data objects (SRDOs). A maximum of 64 SRDOs is possible in the entire CAN network. The Receive SRDOs (Master => Slave) are displayed on the left side and the Transmit SRDOs (Slave => Master) are displayed on the right side.

Basically, each SRDO consists of two CAN telegrams: a telegram with an uneven COB-ID that contains the data, and a telegram with an even COB-ID and bit-inverted data. Then a maximum possible data size of 8 bytes.

Add SRDO	Opens the Select SRDO dialog. The dialog shows the SRDOs defined in the standard. When you select an SRDO in this dialog and confirm it, the SRDO is displayed on the SRDO tab.
Add Mapping	Requirement: An SRDO is selected. The command opens the SRDO Mapping dialog for adding the mapping. The corresponding objects must already be added to the Object directory.
Edit	If an SRDO is selected, then the SRDO Properties dialog opens. If a mapping is selected, then the SRDO Mapping dialog opens.
Delete	Deletes the selected line.
Name	Name of the SRDO and mapping : SRDO is activated by default. : : SRDO is deactivated by default.

The parameters of the SRDOs are shown as tooltips when the mouse pointer is located over the name.

Dialog: SRDO Mapping

In the dialog, the mapping and assignment of the plain data object are defined for the inverse data object.

Plain data object

Double-clicking the line below it opens the Select SRDO Mapping dialog where the applicable elements are displayed from the object directory.

When you select a plain data type in the dialog Select SRDO Mapping and click OK, the data object is added to the SRDO Mapping dialog.

Inverse data object

Double-clicking the line below it opens the Select SRDO Mapping dialog.

When you select an inverse data type in the dialog Select SRDO Mapping and click OK, the data object is added to the SRDO Mapping dialog.

CODESYS checks automatically whether the data type and data length of the plain and the inverse data objects match. The result is shown at the bottom of the dialog.

Dialog: SRDO Properties

Call: Double-click the SRDO on the SRDOs tab.

COB-ID 1:

COB-ID of the CAN telegram that contains the data.

Note: An uneven COB-ID or 0 should be specified in order to comply with the standard.

The tooltip of the input field shows information about the COB-ID.

COB-ID 2:

COB-ID of the CAN telegram that contains the inverse data.

Note: An even COB-ID or 0 should be specified in order to comply with the standard.

The tooltip of the input field shows information about the COB-ID.