Operating Behavior; Start-Up Behavior - Aventics CANopen Instrucciones De Servicio

124 AVENTICS | CANopen | R412005742–BDL–001–AD
Commissioning and operation
Behavior after power on
7.3

Operating behavior

The behavior of the bus connection depends on the CANopen
characteristics as well as the I/O configuration.
CAN frames have a maximum data capacity of 8 bytes. When
using the standards for CiA DS-301 (Master/Slave Connection
Set) 4 channels to send PDOs (Process Data Objects) and 4
channels to receive PDOs can be defined per CAN node.
Since the bus switch takes max. 3 bytes for inputs and 6 bytes
for outputs, 1 receiving and 1 transmitting PDO each is
sufficient.
Only PDOs are transmitted that have a connected I/O module.
Furthermore, one SDO channel (Service Data Object) in the
transmission and receiving directions is available per CAN node.
7.4

Start-up behavior

After the assembly has been switched on (connecting the 24 V
logics supply), the hardware components are tested.
If the start-up test has been successfully completed and the bus
voltage is available, the I/O configuration will be determined.
The CAN controller is then initialised according to the
presettings on the rotary and DIP switches.
The assembly module is in the "Preoperational" condition after
being successfully initialized. It can then be set to the
"Operational" condition by the CAN master with an "NMT
START" telegram. Process data can only be transmitted via the
PDOs after the function module is in the "Operational" mode.
If an error is found, the bus coupler is stopped (see "System
stop" on page 129).