Parameterization and commissioning
CX8050, CX8051 - Embedded-PCs for
CANopen and CAN
41
Version: 1.4
6.3.3
CAN
CX8051
CANopen-Interface
The CANopen communication takes place via D-Sub port X101.
Note
Debug via the Ethernet interface only
The CX8051 does not support the ADS via CANopen. The program download and debug-
ging can take place exclusively via the Ethernet interface.
CANopen address
The CANopen address can be assigned via the rotary selector, or permanently in the System Manager. If the
address is assigned permanently, the address switch is ignored.
CANopen NodeState
The NodeState can be used to display the state of the CANopen communication to find out whether the
slave is engaged in data exchange (NodeState=0) or whether there is an error or problem.
0 = No error
128 = Node is Operational but not all RxPDOs were received
129 = Node is Pre-Operational
130 = Node is Stopped
CANopen process data
The CX8051 can exchange up to 16 PDOs (each with 8 bytes of process data) with the CANopen master in
input and output direction via CANopen.
By default 2 PDOs are created in Tx and Rx direction. The PDOs can be filled with user data. The limit of 8
bytes per PDO must not be exceeded. Data are sent automatically when there is a change, unless the
master is configured differently. At the planning stage please ensure that the data in a PDO "only" change at
a moderate rate (e.g. not with ms frequency). Failure to adhere to this can lead to CAN overload. Particularly
for low baud rates, the CAN can reach its limit quite quickly.
Creating data in the PDO
For each PDO you can create up 8 bytes of data. Variables of different type may be used, as long as the
limit of 8 bytes is adhered to. For TxPDOs there is an additional control word, which can be used in cases
where data are to be sent not only in the event of changes, but also when the data in the PDO have not
changed. To change the control word it can simply be incremented, for example. If incrementation and data
modification happen at the same time (i.e. in the same cycle), only one telegram is sent.
The RxPDOs had an additional status word, which is incremented on arrival of the PDO. This is useful in
Summary of Contents for CX8050
Page 2: ......
