BECKHOFF AX2000 CANopen communication profile - Manual (Page 115)

6 Appendix
6.1 Setup examples
All values are hexadecimal. The axis-related values always refer to Station1.
6.1.1 Basic testing of the connection control<->AX2xxx
When the AX2000/2500 is switched on, an Emergency Message is transmitted over the bus with 0
or 8 data bytes (contents 0), depending on the setting of Bit 2 of the DRVCNFG parameter. The
telegram continues to be transmitted, as long as it has not yet found a suitable receiver in the bus
system.
If a CAN master is unable to recognize this message, then the following measures can be taken to
test communication:
l Check the bus cable: correct characteristic impedance, correct termination resistors at both
ends?
l With a multimeter: check the quiescent level of the bus cables CAN-H and CAN-L against
CAN-GND (approx. 2.5 V).
l With an oscilloscope: check the output signals on CAN-H and CAN-L at the AX2000/2500. Are
signals being transmitted on the bus? The voltage difference between CAN-H and CAN-L for a
logical "0" is approx. 2-3 V.
l Does signal transmission stop if the master is connected? Check the master hardware.
l Check the master software!
CANopen for AX2000/2500 115
BECKHOFF
07/2007
Appendix