RAVEO RM72A User manual

User Manual
RM72A
2-Phase Digital Stepper Drive
Hardware Version 2.0
Manual Revision 1.0

RM72A Digital Stepper Drive User Manual
Table of Content s
1. Introductions ................................................................................................................................................................................................................ 1
1.1 Features ....................................................................................................................................................................................................................... 1
1.2 Applications ................................................................................................................................................................................................................. 1
2. Specifications ................................................................................................................................................................................................................ 1
2.1 Electrical Specifications ................................................................................................................................................................................................ 1
2.2 Environment ................................................................................................................................................................................................................ 2
2.3 Mechanical Specifications ............................................................................................................................................................................................ 2
2.4 Elimination of Heat ...................................................................................................................................................................................................... 2
3. Connection Pin Assignments and LED Indication ........................................................................................................................................................... 3
3.1 P1 - Control Connector ................................................................................................................................................................................................ 3
3.2 P2 - Fault and Brake Output Connector ....................................................................................................................................................................... 3
3.3 P3 - Motor and Power Supply Connector .................................................................................................................................................................... 4
3.4 P4 - Tuning Connector .................................................................................................................................................................................................. 4
3.5 LED Light Indication ..................................................................................................................................................................................................... 4
4. Control Signal and Output Signal .................................................................................................................................................................................. 5
4.1 Control Signal Connection ............................................................................................................................................................................................ 5
4.2 Fault and Brake Output Connection ............................................................................................................................................................................. 5
5. Motor Connection ........................................................................................................................................................................................................ 6
5.1 Connections of 4-lead Motor ....................................................................................................................................................................................... 6
5.2 Connections of 6-lead Motor ....................................................................................................................................................................................... 6
5.2.1 Half Coil Configuration ................................................................................................................................................................................... 6
5.2.2 Full Coil Configuration .................................................................................................................................................................................... 7
5.3 Connections of 8-lead Motor ....................................................................................................................................................................................... 7
5.3.1 Series Connection ........................................................................................................................................................................................... 7
5.3.2 Parallel Connection ......................................................................................................................................................................................... 7
6. Power Supply Selection ................................................................................................................................................................................................. 8
6.1 Regulated or Unregulated Power Supply ..................................................................................................................................................................... 8
6.2 Power Supply Sharing .................................................................................................................................................................................................. 8
6.3 Selecting Supply Voltage .............................................................................................................................................................................................. 8
7. DIP Switch Configurations ............................................................................................................................................................................................. 9
7.1 Microstep Resolution Configurations ........................................................................................................................................................................... 9
7.2 Output Current Configurations .................................................................................................................................................................................... 9
7.2.1 Dynamic Current Configurations .................................................................................................................................................................. 10
7.2.2 Idle Current Configuration ............................................................................................................................................................................ 10
7.3 Control Mode Configurations .................................................................................................................................................................................... 10
7.4 Smoothing Time Configuration .................................................................................................................................................................................. 10
7.3 Automatic Motor Matching & Self Configuration ...................................................................................................................................................... 10
8. Wiring Notes ............................................................................................................................................................................................................... 10
9. Typical Connection ...................................................................................................................................................................................................... 11
10. Sequence Chart of Control Signals ............................................................................................................................................................................. 11
11. Protection Functions ................................................................................................................................................................................................. 12
12. Troubleshooting ........................................................................................................................................................................................................ 13
13. Warranty .................................................................................................................................................................................................................. 14
14. Contact Us ................................................................................................................................................................... Chyba! Záložka není definována.

RM72A Digital Stepper Drive User Manual
Page | 1
1. Introductions
The RM72A is a digital stepper drive with simple design and easy setup. By implementing advanced stepper control
technology, this stepper drive is able to power 2-phase and 4 phase stepper motors smoothly with optimal torque and
low motor heating & noise. Its operating voltage is 18-80VAC or 24-110VDC and it can output up to 7.2A current. All
the micro step and output current configurations can be easily done via built in DIP switches. Its control type (step &
direction or CW/CCW) and command smooth filtering can also be configured via DIP switches. Therefore, the RM72A
are ideal choices for applications requiring simple step & direction control of NEMA 23, 24, 34, and 42 stepper
motors.
1.1 Features
l Step & direction (PUL/DIR) or CW/CCW (double pulse) control
l Input voltage 18-80VAC or 24-110VDC (recommended 20-70VAC or 30-90VDC)
l 200 KHz max pulse input frequency
l 16 microstep resolutions of 400-51,200 via DIP switches, or 200-51,200 via software (increase by 200)
l 8 output current settings of 2.4-7.2A via DIP Switches, or 1.0-7.2A via software (increase by 0.1)
l Configurable control command smoothing for reducing motor vibration
l Idle current reduction to 50% or 90% selection via SW4
l Auto-tuning to match wide-range NEMA 23, 24, 34 and 42 stepper motors
l Anti-Resonance for optimal torque, extra smooth motion, low motor heating and noise
l Soft-start with no “jump” when powered on
l Optically isolated inputs with 5V or 24V
l Fault and Brake outputs
l Over-voltage and over-current protections
1.2 Applications
The RM72A stepper drive are designed to power 2 phase (1.8°) or 4-phase (0.9°) NEMA 23, 24, 34, and 42 hybrid
stepper motors. It can be easily adopted in many industries (CNC, medical, automation, packaging…), such as X-Y
tables, engraving machines, labeling machines, mills, plasma, laser cutters, pick and place devices, and so on. Its
excellent performance, simple design, and easy setup make it ideal for many step & direction control type applications.
2. Specifications
2.1 Electrical Specifications
Parameters
RM72A
Min
Typical
Max
Unit
Output Current
2.4
-
7.2
A
Supply Voltage
18
24
20 - 70
30 - 90
80
110
VA C
VDC
Logic signal current
7
10
16
mA
Pulse input frequency
0
-
200
kHz
Minimal Pulse Width
2.5
-
-
μS
Minimal Direction Setup
5.0
-
-
μS

RM72A Digital Stepper Drive User Manual
Page | 2
Isolation resistance
500
MΩ
2.2 Environment
Cooling
Natural Cooling or Forced cooling
Operating Environment
Environment
Avoid dust, oil fog and corrosive gases
Ambient Temperature
0°C － 65°C (32°F - 149°F)
Humidity
40%RH－90%RH
Operating Temperature
0°C － 50°C (32°F - 122°F)
Vibration
10-50Hz / 0.15mm
Storage Temperature
-20°C － 65°C (-4°F - 149°F)
Weight
Approx. 510g (1.13 lbs)
2.3 Mechanical Specifications
(unit: mm [1inch=25.4mm])
Figure 1 Mechanical specifications
• Side mounting recommended for better heat dissipation
2.4 Elimination of Heat
l RM72A reliable working temperature should be < 60℃ (140°F)
l It is recommended to use automatic idle-current mode to reduce motor heating. That means set the SW4 pin of
DIP switch at “OFF” position.
l It is recommended to mount the drive vertically to maximize heat sink area. Use forced cooling method to cool if
necessary.

RM72A Digital Stepper Drive User Manual
Page | 3
3. Connection Pin Assignments and LED Indication
Figure 2 Connectors, DIP switches, and LED locations
The RM72A has three connector blocks P1&P2&P3 (see above picture). P1 is for control signals connections, and P2
is for output signals connections, P3 is for power and motor connections. The following tables are brief descriptions of
the three connectors. More detailed descriptions of the pins and related issues are presented in section 4, 5, 9.
3.1 P1 - Control Connector
PIN
Details
PUL+ (CW+)
Pulse and Direction Connection:
(1) Optically isolated, high level 4.5-5V or 24V, low voltage 0-0.5V
(2) Maximum 200 KHz input frequency
(3) The width of PUL signal is at least 2.5μs, duty cycle is recommended 50%
(4) Single pulse (step & direction) or double pulse (CW/CCW) is set by DIP Switch SW9
(5) DIR signal requires advance PUL signal minimum 5 μs in single pulse mode
(6) The factory setting of control signal voltage is 24V, must need to set S2 (figure 2) if it is 5V
PUL- (CW-)
DIR+ (CCW+)
DIR- (CCW-)
ENA+
Enable Connection: (default no connection)
(1) Optically isolated, differential.
(2) Disable the drive by 4.5- 24V input connection; enable the drive by 0-0.5V connection
(3) ENA signal requires advance DIR signal minimum 5μs in single pulse mode
(4) Enable time to be at least 200ms
ENA-
Notes:
(1) Shield cables are required for P1;
(2) Don’t tie P1/P2 cables and P3 cables together.
3.2 P2 - Fault and Brake Output Connector
Pin
Details
BRK+
(1) Maximum 30V/100mA output
(4) Brake connection refer to chapter 4.2
BRK-
ALM+
(1) Maximum 30V/100mA output
!"#$%&'!()*+,
!-.-+*/0'"
&1#&/(-0'2'3/*/0'
4/55-+*/0 &6#789.*'85:';08<-''
=9*>9*?
&"#4/5*0/.'!)@58.'%5>9*?
!*8*9?'AB$?'
&C#D95)5@'&/0*
!6#4/5*0/.'!)@58.'E/.*8@-'
!-.-+*/0'FCE'/0'6GEH

RM72A Digital Stepper Drive User Manual
Page | 4
ALM-
(2) Sinking or sourcing
(3) The resistance between ALM+ and ALM- is low impedance as default, and will change to
high when the drive goes into error protection.
(4) Fault connection refer to chapter 4.3
3.3 P3 - Motor and Power Supply Connector
Pin Function
Details
A+, A-
Motor Phase A connections. Connect motor A+ wire to A+ Pin; motor A- wire to A-
B+, B-
Motor Phase B connections. Connect motor B+ wire to B+ Pin; motor B- wire to B-
AC
Power supply input 18-80VAC or 24-110 VDC(recommended 20-70VAC or 30-90VDC);
No polarity
AC
Warning: (1) Don’t plug or unplug the P1 & P2&P3 terminal block to avoid drive damage or injury when
RM72A is powered on. (2) If using an AC transformer, be sure to use a transformer with isolation.Otherwise there is a
risk of electrocution
3.4 P4 - Tuning Connector
RM72A has a tuning port with RS232 to modify the drive parameters, it is just used to modify parameter, not for
equipment control because neither precision nor stability is sufficient. If you need a field bus drive, use a RS485 or
EtherCAT type drives:
The interface definition is as follows:
Figure 3: RS232 connector
3.5 LED Light Indication
There are two LED lights for RM72A. The GREEN one is the power indicator which will be always on generally. The
RED one is a protection indicator which will flash 1-2 times in a 3-second period, when protection enabled for a
RM72A. Different number of flashes indicates different protection type (read section 11 for detail).
!
Warning

RM72A Digital Stepper Drive User Manual
Page | 5
4. Control Signal and Output Signal
4.1 Control Signal Connection
The RM72A can accept can accept differential or single-ended control signals (pulse, direction, and enable) in
open-collector or PNP connection through the P1 connector (figure 2). It is recommend to add an EMI line filter
between the power supply and the drive to increase noise immunity for the drive in interference environments.
Figure 4: Connections to open-collector signal Figure 5: Connections to PNP signal
(common-anode) (common-cathode)
Notes:
(1) When "EAN" is switched on, the engine stops.
(2) ENA signal is no-connected as default;
(3) Control signal amplitude is 24 V as default. If it is 12 V, please set the S2 (Figure 2) selector switch to 5 V first, then
connect 1KΩ resistor; If it is 5V, please set the S2 to 5V.
4.2 Fault and Brake Output Connection
•Fault Output
When over voltage or over current protection happens, RM72A red status LED light will blink and the impedance state
between ALM+ and ALM- will change (from low to high or high to low depending on configuration) and can thus be
detected. Fault output connection is optional, and it can be connected either in sinking or sourcing.
Figure 6 Sinking output Figure 7 Sourcing output
Drive
Controller
VCC
PUL-
PUL+
ENA-
PUL
DIR
ENABLE
DIR-
DIR+
ENA+
Drive
Controller
VCC PUL-
PUL+
ENA-
PUL
DIR
ENABLE
DIR-
DIR+
ENA+

RM72A Digital Stepper Drive User Manual
Page | 6
• Brake Control
It is recommended to connect a fly-wheel diode in parallel to a 24VDC relay and brake coil connection. Refer to the
following figure for brake connection.
Figure 8 Brake output
5. Motor Connection
The RM72A can drive 2-phase and 4-pahse bipolar hybrid stepper motors with 4, 6, or 8 wires.
5.1 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 9: 4-lead Motor Connections
5.2 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.
5.2.1 Half Coil Configuration
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.
+24VDC
GND
Drive
BRK
COM-
Brake
Coil
24VDC relay
+24VDC
GND
Drive
BRK
COM-
Brake
Coil
24VDC solid-
state relay

RM72A Digital Stepper Drive User Manual
Page | 7
Figure 10: 6-lead motor half coil (higher speed) connections
5.2.2 Full Coil Configuration
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 11: 6-lead motor full coil (higher torque) connections
5.3 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.
5.3.1 Series Connection
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 12: 8-lead motor series connections
5.3.2 Parallel Connection
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 13: 8-lead motor parallel connections

RM72A Digital Stepper Drive User Manual
Page | 8
6. Power Supply Selection
The RM72A can power medium and large size stepping motors (frame size from NEMA 23 to 42). To get 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.
6.1 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 and fast response for current change. If you prefer to a
regulated power supply, it is suggested to choose such a power supply specially designed for stepper/servo controls. Or,
in the case when only normal switching power supplies are available, it is important to use “OVERSIZE” high current
output rating power supplies (for example, using a 4A power supply for 3A stepper motor) to avoid problems such as
current clamp. 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.
6.2 Power Supply Sharing
Multiple RM72A drives can share one power supply to reduce cost, if that power supply has enough power capacity.
To avoid cross interference, connect each stepper drive directly to the shared power supply separately. To avoid cross
interference, DO NOT daisy-chain connect the power supply input pins of the Drivers. Instead connect them to power
supply separately.
6.3 Selecting Supply Voltage
The RM72A is designed to operate within 18 - 80VAC or 24-110VDC voltage input. When selecting a power supply,
besides voltage from the power supply power line voltage fluctuation and back EMF voltage generated during motor
deceleration needs also to be taken into account. Please make sure leaving enough room for power line voltage
fluctuation and back-EMF voltage charge back.
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.