StepperOnline DMT556T User manual

User’s Ma
nu a l
For
DM542T
Full Digital Stepper
Dr i ver
Version 1.0
Designed by StepperOnline®
©2017 All Rights Reserved
Web site: www.omc-stepperonline.com
E-Mail: [e-mail]

Table of Contents
1. Introductions, Features and Applications.....................................................................................................................1
Introductions................................................................................................................................................................1
Features........................................................................................................................................................................1
Applications.................................................................................................................................................................1
2. Specifications................................................................................................................................................................1
Electrical Specifications (Tj = 25℃/77℉)................................................................................................................. 1
Operating Environment and other Specifications.......................................................................................................2
Mechanical Specifications (unit: mm [1inch=24.5mm])............................................................................................2
Elimination of Heat.....................................................................................................................................................2
3. Pin Assignment and Description..................................................................................................................................3
Connector P1 Configurations......................................................................................................................................3
Connector P2 Configurations......................................................................................................................................3
4. Control Signal Connector (P1) Interface......................................................................................................................3
Connections of 4-lead Motor...................................................................................................................................... 4
Connections of 6-lead Motor...................................................................................................................................... 4
Half Coil Configurations.....................................................................................................................................4
Full Coil Configurations..................................................................................................................................... 5
Connections of 8-lead Motor...................................................................................................................................... 5
Series Connections..............................................................................................................................................5
Parallel Connections............................................................................................................................................5
5. Power Supply Selection................................................................................................................................................6
Regulated or Unregulated Power Supply....................................................................................................................6
Multiple Drives............................................................................................................................................................6
Selecting Supply Voltage.............................................................................................................................................6
6. Selecting Microstep Resolution and drive Output Current.........................................................................................6
Microstep Resolution Selection.................................................................................................................................. 6
Current Settings...........................................................................................................................................................7
Dynamic Current Setting.....................................................................................................................................7
Standstill Current Setting................................................................................................................................... 8
7. Wiring Notes...................................................................................................................................................................8
8. Typical Connection.........................................................................................................................................................8
9. Sequence Chart of Control Signals...............................................................................................................................9
10. Protection Functions.....................................................................................................................................................9
11. Frequently Asked Questions....................................................................................................................................... 10
Problem Symptoms and Possible Causes...................................................................................................................10

1
DM542T Stepper Driver Manual
1. Introductions, Features and Applications
Introductions
The DM542T is a fully digital stepper drive developed with advanced DSP control algorithm based on the latest
motion control technology. It has achieved a unique level of system smoothness, providing optimal torque and nulls mid-
range instability. Its motor auto-identification and parameter auto-configuration feature offers quick setup to optimal
modes with different motors. Compared with traditional analog drives, DM542T can drive a stepper motor at much
lower noise, lower heating, and smoother movement. Its unique features make DM542T an ideal choice for high
requirement applications.
Features
Anti-Resonance provides optimal torque and nulls mid-range instability
Motor auto-identification and parameter auto-configuration when power on, offer optimal responses with different
motors
Multi-Stepping allows a low resolution step input to produce a higher microstep output, thus offers smoother
motor movement
15 selectable microstep resolutions including 400, 800, 1600, 3200, 6400, 12800, 25600, 1000, 2000, 4000, 5000,
8000, 10000, 20000, 25000
Soft-start with no “jump”when powered on
Input voltage 20-50VDC
8 selectable peak current including 1.00A, 1.46A, 1.91A, 2.37A, 2.84A, 3.31A, 3.76A, 4.20A
Pulse input frequency up to 200 KHz, TTL compatible and optically isolated input
Automatic idle-current reduction
Suitable for 2-phase and 4-phase motors
Support PUL/DIR mode
Over-voltage and over-current protections
Applications
Suitable for a wide range of stepper motors, size from NEMA17 to 24. It can be used in various kinds of machines,
such as X-Y tables, engraving machines, labeling machines, laser cutters, pick-place devices, and so on. Particularly
adapt to the applications with low noise, low heating, high speed and high precision.
2. Specifications
Electrical Specifications (Tj = 25℃/77℉)
Parameters
Output Peak Current
Input Voltage Logic
Signal Current Pulse
input frequency Pulse
Width
Isolation resistance
DM542T
Min Typical Max Unit
1.0 - 4.2 (3.0 RMS) A
+20 +36 +50 VDC
7 10 16 mA
0 - 200 kHz
2.5 - - uS
500 MΩ

2
DM542T Full Digital Stepper Drive Manual
V2.0
Operating Environment and other Specifications
Cooling
Operating Environment
Storage Temperature
Weight
Natural Cooling or Forced cooling
Environment Avoid dust, oil fog and corrosive gases
Ambient Temperature 0℃－65℃
Humidity 40%RH－90%RH
Operating Temperature －10℃－45℃
Vibration 10-50Hz / 0.15mm
-20℃－65℃
Approx. 210g (7.4oz)
Mechanical Specifications (unit: mm [1inch=25.4mm])
Figure 1: Mechanical specifications
*Recommend use side mounting for better heat dissipation
Elimination of Heat
Drive’s reliable working temperature should be <45℃(113 ℉), and motor working temperature should be
<80℃(176℉);
It is recommended to use automatic idle-current mode, namely current automatically reduce to 50% when motor
stops, so as to reduce drive heating and motor heating;
It is recommended to mount the drive vertically to maximize heat sink area. Use forced cooling method to cool
the system if necessary.

3
DM542T Full Digital Stepper Drive Manual
V2.0
3. Pin Assignment and Description
The DM542T has two connectors P1&P2, P1 is for control signals connections, and P2 is for power and motor
connections. The following tables are brief descriptions of the two connectors. More detailed descriptions of the pins
and related issues are presented in section 4, 5, 9.
Connector P1 Configurations
Pin Function
Details
PUL+
Pulsesignal: In single pulse (pulse/direction) mode, this input represents pulse signal, each
rising edge active; 4-5V when PUL-HIGH, 0-0.5V when PUL-LOW. The DM542T drive has
no double pulse mode (pulse/pulse). For reliable response, pulse width should be longer
than 2.5μs. Series connect resistors for current-limiting when +12V or +24V used (1K for
+12V, 2k for +24V). The same as DIR and ENAsignals.
PUL-
DIR+
DIRsignal: In single-pulse mode, this signal has low/high voltage levels, representing two
directions of motor rotation; The DM542T drive has no double pulse mode (pulse/pulse). 4-5V
when DIR-HIGH, 0-0.5V when DIR-LOW. Please note that rotation direction is also related to
motor-drive wiring match. Exchanging the connection of two wires for a coil to the drive will
reverse motor direction.
DIR-
ENA+
Enablesignal: This signal is used for enabling/disabling the drive. High level (NPN control
signal, PNP and Differential control signals are on the contrary, namely Low level for
enabling.) for enabling the drive and low level for disabling the drive. Usually left
UNCONNECTED (ENABLED).
ENA-
Connector P2 Configurations
4. Control Signal Connector (P1) Interface
The DM542T can accept differential and single-ended inputs (including open-collector and PNP output). The
DM542T has 3 optically isolated logic inputs which are located on connector P1 to accept line drive control signals.
These inputs are isolated to minimize or eliminate electrical noises coupled with the drive control signals.
Recommend using line drive control signals to increase noise immunity for the drive in interference environments. In
the following figures, connections to open-collector and PNP signals are illustrated.
Pin Function
Details
GND
Power Ground.
+V
Power supply, 20~50 VDC, Including voltage fluctuation and EMF voltage.
A+, A-
Motor Phase A
B+, B-
Motor Phase B

4
DM542T Full Digital Stepper Drive Manual
V2.0
C on t ro lle r
Drive
Controller
Dr i v e
VCC
PUL
DIR
ENABLE
PUL+
PUL-
DIR+
DIR-
ENA+
ENA-
PUL
DIR
ENABLE
PUL+
VCC
PUL-
DIR+
DIR-
ENA+
ENA-
Figure 2: Connections to open-collector Figure 3: Connections to PNP signal (common-cathode)
signal (common-anode)
Connections of 4-lead Motor
The 4 lead motors are the least flexible and easy to connect. And the Speed –torque of motor depends on winding
inductance. The output current from drive that is multiply the specified phase current by 1.4 to determine the peak
output current.
Figure 4: 4-lead Motor Connections
Connections of 6-lead Motor
Like 8 lead stepping motors, 6 lead motors have two configurations available for high speed or high torque operations.
The higher speed configuration, or half coil, is described, because it uses one half of the motor’s inductor windings.
The higher torque configuration, or full coil, uses the full coil windings.
Half Coil Configurations
As previously stated, the half coil configuration uses 50% of the motor phase windings. This gives lower inductance,
hence, lower torque output. Like the parallel connection of 8 lead motor, the torque output will be more stable at higher
speeds. This configuration is also referred to as half chopper. In setting the drive output current multiply the specified
per phase (or unipolar) current rating by 1.4 to determine the peak output current.
Figure 5: 6-lead motor half coil (higher speed) connections

5
DM542T Full Digital Stepper Drive Manual
V2.0
Full Coil Configurations
The full coil configuration on a six lead motor should be used in applications where higher torque at lower speed is
desired. This configuration is also referred to as full copper. In full coil mode, the motors should be run at only 70% of
their rated current to prevent overheating.
Figure 6: 6-lead motor full coil (higher torque) connections
Connections of 8-lead Motor
8 lead motors offer a high degree of flexibility to the system designer in that they may be connected in series or parallel,
thus satisfying a wide range of applications.
Series Connections
A series motor configuration would typically be used in applications where a higher torque at lower speed is required.
Because this configuration has the most inductance, the performance will start to degrade at higher speed. In series
mode, the motors should also be run at only 70% of their rated current to prevent overheating.
Figure 7: 8-lead motor series connections
Parallel Connections
An 8 lead motor in a parallel configuration offers a more stable, but lower torque at lower speeds. But because of the
lower inductance, there will be higher torque at higher speeds. Multiply the per phase (or unipolar) current rating by
1.96, or the bipolar current rating by 1.4, to determine the peak output current.
Figure 8: 8-lead motor parallel connections

6
DM542T Full Digital Stepper Drive Manual
V2.0
5. Power Supply Selection
The DM542T can match medium and small size stepping motors (frame size from NEMA17 to 34) made by
STEPPERONLINE or other motor manufactures around the world. To achieve good driving performances, it is
important to select supply voltage and output current properly. Generally speaking, supply voltage determines the high
speed performance of the motor, while output current determines the output torque of the driven motor (particularly
at lower speed). Higher supply voltage will allow higher motor speed to be achieved, at the price of more noise
and heating. If the motion speed requirement is low, it’s better to use lower supply voltage to decrease noise, heating
and improve reliability.
Regulated or Unregulated Power Supply
Both regulated and unregulated power supplies can be used to supply the drive. However, unregulated power supplies
are preferred due to their ability to withstand current surge. If regulated power supplies (such as most switching
supplies.) are indeed used, it is important to have large current output rating to avoid problems like current clamp, for
example using 4A supply for 3A motor-drive operation. On the other hand, if unregulated supply is used, one may use a
power supply of lower current rating than that of motor (typically 50% ～70% of motor current). The reason is that
the drive draws current from the power supply capacitor of the unregulated supply only during the ON duration of the
PWM cycle, but not during the OFF duration. Therefore, the average current withdrawn from power supply is
considerably less than motor current. For example, two 3A motors can be well supplied by one power supply of 4A
rating.
Multiple Drives
It is recommended to have multiple drives to share one power supply to reduce cost, if the supply has enough capacity.
To avoid cross interference, DO NOT daisy-chain the power supply input pins of the drives. (Instead, please connect
them to power supply separately.)
Selecting Supply Voltage
The power MOSFETS inside the DM542T can actually operate within +20 ~ +50VDC, including power input
fluctuation and back EMF voltage generated by motor coils during motor shaft deceleration. Higher supply voltage can
increase motor torque at higher speeds, thus helpful for avoiding losing steps. However, higher voltage may cause
bigger motor vibration at lower speed, and it may also cause over-voltage protection or even drive damage. Therefore,
it is suggested to choose only sufficiently high supply voltage for intended applications, and it is suggested to use
power supplies with theoretical output voltage of +20 ~ +45VDC, leaving room for power fluctuation and back-EMF.
6. Selecting Microstep Resolution and drive Output Current
This drive uses an 8-bit DIP switch to set microstep resolution, and motor operating current, as shown below:
Microstep Resolution Selection
Microstep resolution is set by SW5, 6, 7, 8 of the DIP switches as shown in the following table:

7
DM542T Full Digital Stepper Drive Manual
V2.0
Microstep Steps/rev.(for 1.8°motor) SW5 SW6 SW7 SW8
2 400
4 800
8 1600
16 3200
32 6400
64 12800
128 25600
5 1000
10 2000
20 4000
25 5000
40 8000
50 10000
100 20000
125 25000
OFF ON ON ON
ON OFF ON ON
OFF OFF ON ON
ON ON OFF ON
OFF ON OFF ON
ON OFF OFF ON
OFF OFF OFF ON
ON ON ON OFF
OFF ON ON OFF
ON OFF ON OFF
OFF OFF ON OFF
ON ON OFF OFF
OFF ON OFF OFF
ON OFF OFF OFF
OFF OFF OFF OFF
Current Settings
For a given motor, higher drive current will make the motor to output more torque, but at the same time causes more
heating in the motor and drive. Therefore, output current is generally set to be such that the motor will not overheat for
long time operation. Since parallel and serial connections of motor coils will significantly change resulting inductance
and resistance, it is therefore important to set drive output current depending on motor phase current, motor leads and
connection methods. Phase current rating supplied by motor manufacturer is important in selecting drive current,
however the selection also depends on leads and connections.
The first three bits (SW1, 2, 3) of the DIP switch are used to set the dynamic current. Select a setting closest to your
motor’s required current.
Dynamic Current Setting
Peak Current RMS Current SW1 SW2 SW3
1.00A 0.71A
1.46A 1.04A
1.91A 1.36A
2.37A 1.69A
2.84A 2.03A
3.31A 2.36A
3.76A 2.69A
4.20A 3.00A
ON ON ON
OFF ON ON
ON OFF ON
OFF OFF ON
ON ON OFF
OFF ON OFF
ON OFF OFF
OFF OFF OFF
Notes: Due to motor inductance, the actual current in the coil may be smaller than the dynamic current setting,
particularly under high speed condition.

8
DM542T Full Digital Stepper Drive Manual
V2.0
Standstill Current Setting
SW4 is used for this purpose. OFF meaning that the standstill current is set to be half of the selected dynamic current,
and ON meaning that standstill current is set to be the same as the selected dynamic current.
The current automatically reduced to 50% of the selected dynamic current 0.4 second after the last pulse. If the
application needs a different standstill current, please contact STEPPERONLINE.
Motor auto-identification and parameter auto-configuration
The drive will operate the function of motor auto-identification and parameter auto-configuration when power on, and
calculate the optimal parameter using for current control after this processing, then the stepper motor can output
optimal torque.
7. Wiring Notes
In order to improve anti-interference performance of the drive, it is recommended to use twisted pair shield cable.
To prevent noise incurred in PUL/DIR signal, pulse/direction signal wires and motor wires should not be tied up
together. It is better to separate them by at least 10 cm, otherwise the disturbing signals generated by motor will
easily disturb pulse direction signals, causing motor position error, system instability and other failures.
If a power supply serves several drives, separately connecting the drives is recommended instead of
daisy-chaining.
It is prohibited to pull and plug connector P2 while the drive is powered ON, because there is high current flowing
through motor coils (even when motor is at standstill). Pulling or plugging connector P2 with power on will cause
extremely high back-EMF voltage surge, which may damage the drive.
8. Typical Connection
A complete stepping system should include stepping motor, stepping drive, power supply and controller (pulse
generator). A typical connection is shown as figure 9.
Figure 9: Typical connection

9
DM542T Full Digital Stepper Drive Manual
V2.0
9. Sequence Chart of Control Signals
In order to avoid some fault operations and deviations, PUL, DIR and ENA should abide by some rules, shown as
following diagram:
Remark:
Figure 10: Sequence chart of control signals
a) t1: ENA must be ahead of DIR by at least 5s. Usually, ENA+ and ENA- are NC (not connected). See
“Connector P1 Configurations” for more information.
b) t2: DIR must be ahead of PUL effective edge by 5s to ensure correct direction;
c) t3: Pulse width not less than 2.5s;
d) t4: Low level width not less than 2.5s.
10. Protection Functions
To improve reliability, the drive incorporates some built-in protections features.
Priority Time(s) of
Blink
Sequence wave of red LED Description
Over-current protection activated when peak
1st 1
current exceeds the limit.
2nd 2 Over-voltage protection activated when drive
working voltage is greater than 60VDC
When above protections are active, the motor shaft will be free or the red LED blinks. Reset the drive by repowering it
to make it function properly after removing above problems.

DM542T Full Digital Stepper Drive Manual
V2.0
10
11.Frequently Asked Questions
In the event that your drive doesn’t operate properly, the first step is to identify whether the problem is electrical or
mechanical in nature. The next step is to isolate the system component that is causing the problem. As part of
this process you may have to disconnect the individual components that make up your system and verify that they
operate independently. It is important to document each step in the troubleshooting process. You may need this
documentation to refer back to at a later date, and these details will greatly assist our Technical Support staff
in determining the problem should you need assistance.
Many of the problems that affect motion control systems can be traced to electrical noise, controller software
errors, or mistake in wiring.
Problem Symptoms and Possible Causes
Symptoms Possible Problems
Motor is not rotating
Motor rotates in the wrong direction
The drive in fault
Erratic motor motion
Motor stalls during acceleration
Excessive motor and drive heating
No power
Microstep resolution setting is wrong
DIP switch current setting is wrong
Fault condition exists
The drive is disabled
Motor phases may be connected in reverse
DIP switch current setting is wrong
Something wrong with motor coil
Control signal is too weak
Control signal is interfered
Wrong motor connection
Something wrong with motor coil
Current setting is too small, losing steps
Current setting is too small
Motor is undersized for the application
Acceleration is set too high
Power supply voltage too low
Inadequate heat sinking / cooling
Automatic current reduction function not being utilized
Current is set too high