NORD Drivesystems BU0210 - Manual (Page 17)

3 Function description
BU 0210 GB Subject to technical amendments 17
3.2.2.1 Resetting the CANopen absolute encoder
By means of the two functions "Reference Point Run" (See Section 3.2.1.1) and "Reset Position" (See Section
3.2.1.2) a CANopen absolute encoder can also be moved to the value "0" or the value set in parameter P609
[02] "Offset Position"
As the resetting of the position in the CANopen absolute encoder takes somewhat longer than the resetting of
an incremental encoder, the speed selected during the resetting procedure should be as low as possible, as
otherwise large differences may occur.
If both an incremental encoder and a CANopen absolute encoder are connected to the frequency inverter, both
encoders can be reset by the performance of the functions "Reference Point Run" or "Reset Position".
3.2.2.2 Settings of the CANopen absolute encoder
The baud rate and the CAN address must be set on the encoder. For the assignment of the switches on the
encoder, please refer to the manufacturer´s operating instructions.
The CAN address for the absolute encoder should be set in parameter P515
1 "CAN Address" according to the
following formula:
Encoder CAN address = SK 2x5E CAN address (P515) + 1
The CAN baud rate set in the encoder must be identical to the parameter P514 "CAN Baud Rate" in SK 2x5E
and all other participants in the bus system. If parameterisation of the encoder is carried out via the SK 2x5E,
the transmission cycle for the absolute encoder position is simultaneously set via the baud rate.
For the operation of several CANopen absolute encoders on a bus system, e.g. for synchronous operation,
different transmission cycle times can be set for the system bus master and the CANopen absolute encoders.
With the parameter P552 "System Bus Master Cycle Time" the cycle time for the system bus master mode can
be parameterised in Array [01] and for the CANopen absolute encoder in Array [02]. Care must be taken that
the parameterised values are not lower than the values in the column for the minimum values of the actual
cycle time. This value depends on the baud rate set in parameter P514 "CAN Baud Rate".
P514
Baud rate
[kBaud]
P552 [01]
Default system bus
master [ms]
P552 [02]
Default CANopen
Absolute encoder
[ms]
P552 [02]
Minimum value for
actual cycle time
[ms]
Bus load caused by
an encoder
[%]
10 50 20 10 42.5
20 25 20 10 21.2
50 10 10 5 17.0
100 5 5 2 17.0
125 5 5 2 13.6
250 5 2 1 17.0
500 5 2 1 8.5
1000
2 5 2 1 4.25
Table 1: Encoder cycle time dependent on the baud rate
1 Alternatively, the baud rate and the address can also be set with DIP switches (See BU 0200)
2 Only for testing purposes. Reliable operation is not guaranteed.