CANopen devices

CANopen devices which are not recognized by the TwinCAT System Manager can be incorporated into the network by selecting the box ”CANopen Node”. The CAN(open) messages (PDOs) can be configured directly for these devices. This will guarantee the optimum flexibility of this general CANopen interface.

When using the FC510x / EL6751, this box also enables you to receive and send any CAN identifier - this enables communication with any CAN node. The only condition is the support of at least one of the baud rates supported by the FC510x / EL6751.

"CAN Node" tab

Node ID
Enter the general CANopen device node address here. If you select the ”Auto Adapt PDO COB Ids" box, the default identifier for the process data object can also be carried out after changing the node ID.

Profile no.
After CANopen, the parameter 0x1000 "Device Type" contains the number of the supported device profile in both the lowest value bytes. These are entered here and compared at the system StartUp with the device parameters present. If no device profile is supported, the parameter will contain the value 0.

Add info
The additional info is located in both the highest value bytes of the object directory entry 0x1000 (device type).

A set/actual configuration comparison is only made if the profile no. or add. info (i.e. object directory entry 0x1000) is set to a value other than zero. If the expected data at the system start do not comply with the values present, the StartUp of this node will be interrupted and a corresponding error message will appear in the Diag Tab.

Guard time
The guard time determines the interval in which the node is monitored (node guarding). 0 signifies no monitoring. The value entered is rounded up to the next multiple of 10 ms.

Lifetime factor
Guard time x lifetime factor determines the watchdog length for the mutual monitoring of card and CANopen nodes. 0 indicates that the CANopen node is not monitoring the card. At 0 the card takes the guard time directly as the watchdog length.

The FC 510x / EL6751 also support the Heartbeat protocol and initially attempt to start this form of node monitoring on the CANopen node (write access to the objects 0x1016 and 0x1017 in the object dictionary). If this attempt fails, guarding is activated. The guard time as producer heartbeat time and (guard time x lifetime factor) as consumer heartbeat time are entered. In this case a Heartbeat telegram is transmitted with the smallest configurable guard time (the guard times can be individually set for each node).

Emcy COB Id / Guard COB ID
Identifier for emergency messages or guarding protocol. They result from the node address.

Use Heartbeat
Heartbeat is used for monitoring of the node. If this is deactivated, the guarding is used for monitoring.

Auto-adjust PDO...
Specifies whether TwinCAT should download the PDO communications parameters to the node at the system start.

If the download of the PDOs Parameter Identifier and Transmission Type fails, the card attempts to read these parameters and compare them with the configured values. In this way, it supports only those nodes which, e.g. have implemented the default identifiers as read-only values.

Vendor ID, Product Code, Serial No., Revision No.
If values other than zero are entered here, these identity object inputs (0x1018 in the object directory) are read off at the system StartUp and compared with the configured values. The corresponding node will be started only if the values coincide. It is also possible to compare one part of the value (e.g. vendor ID and product code) - in this case set the not desired parameters to zero.

Node error reaction

Stop Node
After a recognized node error, the node is set to "Stopped" mode (NMT command "Stop Remote Node"). The node (according to each device profile) can then be switched to a safe mode via the network status machine - SDO addressing is not possible in this mode.
no response
No NMT stop remote node command after node error

Node Restart

Automatic Restart
After a recognized node error the card automatically attempts to restart the node. The StartUp attempt is initiated by a node reset command.
Manual Restart
After a node error, this node remains in error mode and is not restarted automatically. You can actuate a restart via "I/O-Reset" .

Network response

no response
The failure of a node has no effect on the other bus devices
All Nodes Stop
After the failure of a node, all other previously started nodes are stopped (NMT stop remote node command). You then need to restart the system.

General CAN Node
If you have selected this checkbox, the entire CANopen network management for this device is deactivated. It is not started, monitored etc. The PDO inputs are detected as pure CAN (2-layer) telegrams and enable the controller to operate in event driven mode.

	CANopen terminology As the CANopen terminology is retained, even in the case of the general CAN nodes, you need to take into account the fact that RxPDOs are the telegrams sent by the FC510x / EL6751 and TxPDOs are the received telegrams. This option allows any CAN node to be connected to the TwinCAT, if the Baud Rate and the bit timing parameters comply. The respective protocol can then be simulated within the PLC program. It is also possible to run CANopen devices and general CAN nodes within the same network - if there are no identifier overlaps (the system structure is such that you cannot use an identifier twice).

CANopen PDOs

Process Data Objects (PDOs) are CAN telegrams which transport process data without a protocol overhead. RxPDOs are received by node, TxPDOs are sent by the node. This description is contained in the System Manager from the perspective of the configured node, i.e. RxPDOs are sent by the TwinCAT, TxPDOs are received by the TwinCAT.

”PDO" tab

COB Id
The CAN identifier of this PDO. For every two send and receive PDOs per node, CANopen provides Default Identifiers. These can then be changed.

Trans.Type
The Transmission Type determines the send behavior of the PDO. 255 corresponds to the event driven send.

Inhibit Time
Send Delay between two identical PDOs. Is entered in multiples of 0.1 ms.

Length
The length of the PDO is based on the mapped variables and cannot therefore be edit here.

Event time (FC510x and EL6751 only)
Enter the value for the Event Timer in ms. For send PDOs (here: RxPDOs, see above) the StartUp of this timer triggers an additional PDO send, for receive PDOs (here: TxPDOs) the arrival of a PDO within the pre-set value is monitored and the box state of the node is changed as appropriate. If 0, the parameter is not transferred to the node.

TwinCAT creates corresponding inputs in the node object directory on the basis of the parameters entered here. These are transferred via SDO at the system start. You can view the inputs at the SDO tab. If this behavior is not required, you can deactivate "Auto Download of PDO Parameters" by selecting the checkbox at the CAN node tab.

Deactivate checking of the PDO size
Checkbox for deactivation of the length check of the PDO size.

Tree Representation:

CANopen devices 4: — TwinCAT tree: CANopen Box

TwinCAT firstly provides two send and receive PDOs, with Default Identifiers, 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 always 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:

CANopen devices 6: — 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.

"SDOs" tab

SDO inputs sent to the node at StartUp are displayed/managed on this page. Inputs with an object index in straight brackets are automatically created on the basis of the updated terminal configuration. Other inputs can be managed using ”Add", ”Insert", ”Delete" and ”Edit".

“ADS” tab

In order to be able to read and write SDO objects during the running time (e.g. from the PLC), the node (Bus Coupler) can be allocated an ADS port (CIFx0-CAN). The FC510x / EL6751 provides an ADS port at all times for every node since the diagnostic information is transported via ADS. These ports can be used to read and write SDO objects using ADS read requests and/or write requests.

The ADS IndexGroup contains the CANopen object index and the ADS IndexOffset contains the CANopen Sub-Index.