SMD23E2 & SMD24E2 S
PECIFICATIONS
SMD23E2 and SMD24E2 User’s Manual
ADVANCED MICRO CONTROLS INC.
16
Indexer Functionality (continued)
Stall Detection with SMD23E2 and SMD24E2 Units
Stall Detection
is one of the additional features available to you when you order an encoder option on an
SMD23E2 or SMD24E2. When Stall Detection is enabled, the unit monitors the encoder for position
changes, regardless of whether or not a move is in progress. If the error between the encoder position and the
motor position exceeds forty-five degrees, the SMD23E2 or SMD24E2 responds in the following manner:
The stall is reported in the network input data.
The motor position becomes invalid. (The machine must be homed or the motor position preset before
Absolute moves can be run again.
If a move was in progress, the move is stopped.
Note that a move does not have to be in progress for stall detection to be useful. As described later in this
chapter, there is an auxiliary power pin that powers the electronics of an SMD23E2 or SMD24E2 but does not
power the motor. The primary use of this feature is to keep the unit on the network while power is removed
from the motor. When using the DCPower
AUX
pin, the SMD23E2 or SMD24E2 cannot sense when power has
been removed from the DCPower
MAIN
pin. By enabling stall detection, the unit can notify the system if the
motor shaft moves more than forty-five degrees while power is removed from the motor.
Driver Functionality
This table summarizes the features of the stepper motor driver portion of the SMD23E2 and SMD24E2 units.
Table R1.2 Driver Functionality
Feature
Benefits
RMS Current Control
RMS current control gives an SMD23E2 or SMD24E2 the ability to drive
the motor at its fully rated power regardless of the programmed steps per
turn. There is no reduction in power when microstepping that may occur
with other drivers.
Programmable
Motor Current
RMS current supplied to the motor can be programmed from 0.1 to 3.4 amps
in 0.1 amp increments. Reducing the motor current to the minimum needed
for your application will significantly reduce the motor’s operating tempera-
ture
Programmable Idle
Current Reduction
Extends motor life by reducing the motor current when motion is not
occurring. This extends the life of the motor by reducing its operating
temperature.
Programmable
Motor Steps/Turn
Allows you to scale your motor count to a real world value. (counts per inch,
counts per degree, etc.)
Anti-Resonance Circuitry
This feedback circuitry and algorithm gives the SMD23E2 and SMD24E2
the ability to modify motor current waveforms to compensate for mechanical
resonance in your system. This will give you smooth performance over the
entire speed range of the motor.
Over Temperature
Detection
An SMD23E2 or SMD24E2 sets a warning bit in the network data when the
internal temperature of the unit approaches its safe operating threshold.
Over Temperature
Protection
Protects your SMD23E2 or SMD24E2 from damage by removing power
from the motor if the internal temperature of the driver exceeds the safe
operating threshold of 203°F/95°C.
