Technical manual
SMCP33
Overview
1 Overview
Introduction
The SMCP33 stepper motor control is an extremely compact and cost-effective
constant current final 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.
The plug-in module can be integrated in complex device control systems with a
minimum of additional development effort, especially for the direct and virtually noise-
free and resonance-free control of the output stages via the microcontroller by means
of the dspDrive® method – both in open-loop and closed-loop operation.
In conjunction with the integrated NanoJ programming language based on the Java
standard, complete sequencing programs can be implemented on the plug-in module
that can be run autonomously without a superordinate controller.
Variants
The SMCP33 is available in the following variants:
•SMCP33: 2 A phase current
•SMCP33-K: with a heat sink for 4 A phase current
Functions of the SMCP33
The SMCP33 stepper motor control contains the following functions:
•Microstep 1/1 – 1/64 final output stage (0.014° step resolution)
•Closed-loop current control (sinusoidal commutation via the encoder)
•Powerful DSP microprocessor for flexible I/O
•Sequence programs with NanoJ
•Rotation monitoring for optional encoder
•RS485 port for parameterisation and control
•Network capability with up to 255 controllers
•The function of the 16 digital inputs and outputs and the two analogue inputs is
freely configurable
•Easy programming with the NanoPro Windows software
Closed-loop current control (sinusoidal commutation via the encoder):
In contrast to conventional stepper motor controls where only the motor is actuated or
the position adjusted via the encoder, sinusoidal commutation controls the stator
magnetic field as in a servomotor via the rotary encoder. 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 recognises 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.
Issue: V 1.1 - 01.02.2010 5
