Beckhoff EL6751 Documentation page 92

Parameterization and commissioning
Tree Representation:
Fig. 108: TwinCAT tree: CANopen Box
TwinCAT firstly provides two send and receive PDOs, with Default Identifiers [} 119], for a general CANopen
node. Superfluous PDOs can be selected and removed.
TxPDOs are sent by the CANopen node and generally contain inputs. RxPDOs are received by the node,
i.e., sent by TwinCAT.
Add variables to the PDOs by right clicking on "Inputs" and/or "Outputs" and selecting the corresponding
variable(s). If several variables of the same type are inserted with a single action, the offset within the PDO
will be created automatically. If variables are inserted one after another, you need to set the corresponding
offset (start address within the CAN telegram) for each variable.
Object dictionary entries in TwinCAT
TwinCAT places the PDOs in the displayed order according to the object dictionary entries in the
node. This way, for example, the PDO communication parameters of the third listed TxPDO are al-
ways written to index 0x1802 – independent of the designation of the PDO in the System Manager.
Thus, if only PDO1 and PDO3 are to be used, a PDO2 must also be entered – in this case without
assigning variables. PDOs without variables are not transmitted and also not expected.
Context menu:
Fig. 109: Context menu for inserting further Tx or Rx-PDOs.
The menu above is obtained by right clicking on the general CANopen node. Here you can insert further Tx
PDOs and/or Rx PDOs.
92 Version: 3.5 EL6751