BECKHOFF AX2000 CANopen communication profile - Manual (Page 11)

2.2 CANopen interface
The interface for connection to the CAN-bus (default : 500 kBaud). The interface is at the same
electrical potential as the RS232 interface. The analog setpoint inputs can still be used.
We can supply special clamp-sleeve connectors, that can easily be made up for bus operation.
In addition, an adapter can be used for the option slot (Option -2CAN-), which provides options for
pass-through wiring and the attachment of 120
W termination resistors. The pin assignments corre-
spond to ISO 11898 (CAN).
For the purpose of equipotential bonding, AGND must be connected to the controller! For
additional information, see the servo amplifier Product Manual.
2.3 CAN-bus cable
In accordance with ISO 11898 you should use a bus cable with a characteristic impedance of 120 W.
The usable cable length for reliable communication is reduced as the transmission rate is increa-
sed. The following values that we have measured can be used as a guide. They should not, howe-
ver, be interpreted as limiting values:
Cable data:
characteristic impedance 100 ... 120
W
cable capacitance max. 60 nF/km
lead resistance (loop) 159.8 W/km
Cable length, dependent on the transmission rate
Transmission rate: kbit/s Max. cable length: m
1000 20
500 70
250 115
Longer transmission distances may be achieved with a lower cable capacitance (max. 30 nF/km)
and lower lead resistance (loop, 115
W/km).
(characteristic impedance 150 ± 5 W Þ termination resistance 150 ± 5W).
For EMC reasons, the SubD connector housing must fulfill the following requirements:
— metal or metallic housing
— provision for connecting the cable shielding in the housing, with a large contact area.
The BECKHOFF company can supply special clamp-sleeve connectors (Order No. DE-90650), that
can easily be made up for bus operation.
In addition, an adapter can be used for the option slot (Option -2CAN-, Order No. 101174), which
provides options for pass-through wiring and the attachment of 120
W termination resistors. The pin
assignments correspond to the CANopen standard DS 301.
CANopen for AX2000/2500 11
BECKHOFF
07/2007
Installation / Setup
AX2000/2500