Technical Manual
SMCI47-S V2.0
Overview
Issue: V 2.2 5
1 Overview
Introduction
The stepper motor control SMCI47-S is an extremely compact and cost-effective
constant current power output stage with integrated Closed-Loop current control.
Due to the great capacity and functions available, it offers designers and developers a
rapid and simple method of resolving numerous drive requirements with less
programming effort.
It is used for controlling standard stepper motors (including with attached encoders) or
motors with integrated encoders or brakes.
Variants
The SMCI47-S is available in the following variants:
•SMCI47-S-2: For control via RS485
•SMCI47-S-3: For control via CANopen
SMCI47-S functions
The stepper motor control SMCI47-S contains the following functions:
•Microstep -1/1 – 1/64 final output stage (step resolution of up to 0.014° in motor
with a step angle of 0.9° in 1/64 step mode)
•Closed-Loop current control (sinusoidal commutation via the encoder)
•Powerful DSP microprocessor for flexible I/O
•Rotation monitoring for optional encoder
•RS485/CANopen interface for parameterization and control (USB connection
possible via converter cable ZK-RS485-USB)
•Network capability with up to 254 motors (RS485) or 127 motors (CANopen)
•Easy programming with Windows software NanoPro (RS485) or NanoCAN
(CANopen)
Closed-Loop current control (sinusoidal commutation via the encoder):
In contrast to conventional stepper motor positioning controls where only the motor is
actuated or the position adjusted via the encoder, sinusoidal commutation controls the
stator magnetic field via the rotary encoder as in a servomotor. The stepper motor acts
in this operating mode as nothing more than a high pole servomotor, i.e. the classic
stepper motor noises and resonances vanish. As the current is controlled, the motor
can no longer lose any steps up to its maximum torque.
If the controller recognizes that the rotor is falling behind the stator field due to
overload, adjustments are made with optimal field angle and increased current. In the
opposite case, i.e. if the rotor is running forward due to the torque, the current is
automatically reduced so that current consumption and heat development in the motor
and controller are much lower compared to normal controlled operation.
