Technical Manual N5 (CANopen)
5 General concepts
•
In object 2030
h
(Pole Pair Count), enter the number of pole pairs (see motor data sheet: for
a stepper motor with 2 phases, a step angle of 1.8° corresponds to 50 pole pairs and 0.9°
corresponds to 100 pole pairs).
•
In object 2031
h
(Max Current), enter the maximum current in mA (see motor data sheet).
•
In object 3202
h
(Motor Drive Submode Select), set bit 0 (CL/OL) to the value "0".
•
If the clock-direction mode is to be used, then observe chapter Clock-direction mode.
If necessary, current reduction on motor standstill should be activated to reduce the power loss and
heat build-up. To activate current reduction, the following settings are necessary:
•
In object 3202
h
(Motor Drive Submode Select), set bit 3 (CurRed) to "1".
•
In object 2036
h
(Open Loop Current Reduction Idle Time), the time in milliseconds is specified that
the motor must be at a standstill before current reduction is activated.
•
In object 2037
h
(Open Loop Current Reduction Value/factor), the root mean square is specified to
which the rated current is to be reduced if current reduction is activated in open loop and the motor
is at a standstill.
Optimizations
Depending on the system, resonances may occur in open loop mode; susceptibility to resonances
is particularly high at low loads. Practical experience has shown that, depending on the application,
various measures are effective for largely reducing resonances:
•
Reduce or increase current, see object 2031
(Max Current). Excessive torque reserve promotes
resonances.
•
Reduce or increase the operating voltage, taking into account the product-specific ranges (with
sufficient torque reserve). The permissible operating voltage range can be found in the product data
sheet.
•
Optimize the control parameters of the current controller via objects 3210
h
:09
h
(I_P) and 3210
:0A
h
(I_I).
•
Adjustments to the acceleration, deceleration and/or target speed depending on the selected control
mode:
Profile Position operating mode
(Profile Acceleration), 6084
h
(Profile Deceleration) and 6081
h
(Profile
Velocity).
Velocity operating mode
(Velocity Acceleration), 6049
h
(Velocity Deceleration) and 6042
h
(Target
Velocity).
Profile Velocity operating mode
(Profile Acceleration), 6084
h
(Profile Deceleration) and 6081
h
(Profile
Velocity).
Homing operating mode
h
:01
h
(Speed During Search For Switch) and
:02
h
(Speed During Search For Zero).
Interpolated Position Mode operating mode
The acceleration and deceleration ramps can be influenced with the higher-level controller.
Cycle Synchronous Position operating mode
The acceleration and deceleration ramps can be influenced via the external "position
specification / time unit" targets.
Cycle Synchronous Velocity operating mode
The acceleration and deceleration ramps can be influenced via the external "position
specification / time unit" targets.
Version: 2.0.1 / FIR-v1650
43
