ETC MSE570

MSE570 Bipolar Stepper
Motor Drive Board
Data Sheet
Specifications
External connections
Bipolar stepper motor drive with optional thermal
protection and on board oscillator.
External connections are made via a 32 way a & c
DIN41612 type D connector.
Electrical
The MSE562 is a suitable power supply unit to power up
to two MSE570 drives.
Motor supply:
+15 to +36Vdc (+10% max.) smoothed unregulated.
Logic supply:
+15 to +24Vdc (+10% max.) smoothed unregulated.
Note: the motor and logic may share the same power
supply up to +24V or up to +36V if a suitable dropper
resistor is fitted in the logic supply line.
Auxiliary outputs (available for external circuitry):
+12V regulated 50mA maximum
+5V regulated 50mA maximum
Motor drive output:
Bipolar chopped constant current with overload
protection. Suitable for driving hybrid or permanent
magnet stepper motors with 4,6 or 8 leads.
Maximum output current 3.5A per phase.
Output current set by on-board DIP switches or external
programming resistor.
Control inputs:
CMOS schmitt trigger inputs operating at +12V with
10KΩ pull-up resistors and diode isolation.
Logic 0 (low) - 0V to +2V or contact closure to 0V.
Logic 1 (high) - +9V to +30V maximum or open circuit.
c
a
4
6
8
10
12
14
16
18
20
22
24
28
Phase A output
Phase A’ output
Phase B output
Phase B’ output
Sync input/output
Home output
Direction (CW/CCW)
Step pulse input
Full/half step input
Reset input
Output disable input
Current program input
Overload output
Overtemperature output
VCO speed control input
VCO pulse output
where
fitted
VCO base speed input
VCO run/stop input
Auxiliary +12V output (50mA maximum)
Auxiliary +5V output (50mA maximum)
Logic supply (+15 to +24Vdc)
30
32
Mechanical and physical
Card size:
Eurocard format 160 mm long x 100 mm wide x 62 mm
high.
0V common
Supplies
Pins 2 a & c
Motor supply input. Should be smoothed unregulated
between +15V and +36V maximum.
Weight:
700g approximately.
Connector:
32 way a & c DIN41612 type D.
Pins 28 a & c
Logic supply input. Should be smoothed unregulated
between +15V and +24V maximum.
Operating temperature range:
0°C to 40°C maximum ambient.
MSE570 data sheet
Motor supply (+15V to +36Vdc)
2
26
Monitor outputs:
Open collector NPN transistor, referenced to 0V.
Low level - +1V maximum at 30mA maximum.
High level - open circuit +24V dc maximum.
If using common
supplies (≤24V)
Pins 30 a & c, 32 a & c
0V common.
Page 1 of 5
Issue 002
Motor
Control inputs
Pins 4 a & c, 6 a & c
Motor phase A should be connected between 4 a & c
and 6 a & c.
Pin 14 a
Direction control input. Pulling this input low will reverse
the direction of rotation of the motor
Pins 8 a & c, 10 a & c
Motor phase B should be connected between 8 a & c
and 10 a & c.
Pin 14 c
Step pulse input. The motor will increment one step on a
high to low transition on this input. The pulse should be
low for 10µS minimum. Maximum frequency 20KHz.
Phase A
Phase A’
Phase B
Phase B’
4 lead motor
max drive current = motor phase current rating
Pin 16 a
Full/half step control input. If this input is high (or
unconnected), full step drive will be generated giving
200 steps per revolution of a hybrid stepper motor. If it is
pulled low, then half step drive will be generated giving
400 steps per revolution. This input would not normally
be changed during use as the unit may enter a wave
drive mode (full step with only one phase on).
The use of half step reduces problems with resonance.
Pin 16 c
Reset input. Pulling this input low will set the internal
logic to give the home phase output and therefore the
home output will be on. This may also be used to reset
an error condition such as overload or overtemperature.
Phase A
Phase A’
Phase B
Phase B’
6 lead motor - both coils
max drive current = motor phase current rating / √2
Pin 18 a
Output disable input. Pulling this input low will disable
the motor output current. There will then be no motor
torque and it may be rotated by hand.
Phase A
These control inputs are CMOS schmitt trigger inputs
operating at +12V with 10KΩ pull-up resistors and diode
isolation. The control options are as follows:
Phase A’
Phase B
Phase B’
Input
6 lead motor - one coil
max drive current = motor phase current rating
0V common
CMOS output operating at +12V
Phase A
Phase A’
Input
Phase B
0V common
Phase B’
8 lead motor - coils in parallel
max drive current = motor phase current rating x √2
Open collector TTL output (e.g. 7406, 7407)
Input
Phase A
Phase A’
0V common
Opto isolator
Phase B
Phase B’
8 lead motor - coils in series.
max drive current = motor phase current rating / √2
To reverse sense or direction swap the connections to
one phase. E.g. swap phase B with phase B’.
MSE570 data sheet
Page 2 of 5
Input
0V common
Switch
Issue 002
Monitor outputs
On board oscillator (option)
Pin 12 c
Home phase output. This output is low when the output
phases are in their initial home state pattern. This state
is repeated in four full steps or eight half steps.
Pin 22 a
VCO speed control input. Applying a control voltage
between 0V and +12V will proportionally vary the output
frequency of the voltage controlled oscillator (if fitted).
Pins 20 a
Overload output. This output will go low and remain
latched low, if an overload or short circuit is detected.
The motor output will also be disabled. This condition
may be reset by either pulling the reset input low or
removing the power
Pin 22 c
VCO output. This 12V CMOS output of the voltage
controlled oscillator (if fitted) may be connected directly
the step pulse input (14 c).
Pins 20 c
Overtemperature output. This output will go low if the
thermal sensor option is fitted and the heatsink gets too
hot. This condition may be latched by setting SW1-2
(LT) on so that the drive doesn’t suddenly become
active when the heatsink cools. This condition may be
reset by either pulling the reset input low or removing
the power. The motor output may also be disabled
automatically by setting SW1-1 (DT) on. If no thermal
sensor is fitted then this output will be low.
Current programming
Pin 18 c
Current program input. The motor current may be
reduced from the value set on the DIP switch by
connecting a resistor from this input to 0V. This may be
used to set the phase current by the connector the unit
is plugged into, or to reduce the motor current on
application of an external signal such as at standstill.
Multi-axis synchronisation
Pin 12 a
Sync input/output. This connection may be used to
synchronise the chopping frequency between a number
of drive cards by connecting them together. One drive is
selected as the master; the others are slaves and
should have their chopping oscillators disabled by
setting SW1-4 on.
Auxiliary power outputs
Pin 26 a
Auxiliary +12V output. 50mA maximum.
Pin 24 c
VCO run/stop input. Pulling this input low enables the
voltage controlled oscillator (if fitted).
Configuration
A four way DIP switch is provided for certain
configuration options.
SW1-1 (DT)
Disable on overtemperature. If this switch is on and the
thermal sensor (option) gets too hot, then the motor
output will be automatically disabled to prevent
overheating. If no thermal sensor is fitted, then this
should be left off.
SW1-2 (LT)
Latch overtemperature. If this switch is on and the
thermal sensor (option) gets too hot, then the
overtemperature condition will be latched. This will
prevent unexpected re-energisation of the drive, when
the heatsink cools back down. The latched condition
may be reset by either pulling the reset input low or
removing the power.
SW1-3 (CC)
Current control type. This switch determines whether the
current control chopping is executed on the upper drive
transistors or the lower drive transistors. This would
normally be left off for more efficient use, but may have
small advantages of current control on low current
settings.
SW1-4 (SS)
Slave sync. If this switch is on, the chopping oscillator is
inhibited. This should only be used on slave units in
multi-axis synchronised systems, where another unit
provides a master chopping signal.
Pin 26 c
Auxiliary +5V output. 50mA maximum.
MSE570 data sheet
Pin 24a
VCO base speed control. A resistance to 0V sets the
base speed of the voltage controlled oscillator (if fitted).
Page 3 of 5
Issue 002
Motor current setting
Status LED’s (user fit option)
The output current per phase is normally set using a
four way DIP switch as follows:
Provision has been made for the user to fit five status
light emitting diodes. These may be soldered into their
locations at the front of the board.
Switch setting
SW2-1 SW2-2
off
off
off
off
off
off
off
off
off
on
off
on
off
on
off
on
off
on
off
on
off
on
off
on
on
on
on
on
on
on
on
on
SW2-3
off
off
on
on
off
off
on
on
off
off
on
on
off
off
on
on
SW2-4
off
on
off
on
off
on
off
on
off
on
off
on
off
on
off
on
Nominal output
current per phase
0.0A
0.5A
0.9A
1.2A
1.3A
1.6A
1.85A
2.1A
2.3A
2.5A
2.7A
2.9A
3.0A
3.1A
3.3A
3.5A
LED1
LED2
LED3
LED4
LED5
green
yellow
red
red
yellow
power is on
output is disabled
overtemperature fault detected
overload fault detected
home phase output
On board oscillator (user fit option)
A simple voltage controlled oscillator may be
constructed on the drive board by the addition of a few
components. These parts are located at the lower front
of the board at the edge and may be soldered in without
removal of the heatsink. The output of this oscillator may
be connected directly to the step pulse input (pin 14c).
The above setting are approximate and may be
influenced by the motors resistance and inductance.
The output current should ideally be checked during
commissioning, using an analogue meter.
The motor current may be reduced from the value set on
the DIP switch by connecting a resistor from the current
program input to 0V. This may be used to set the phase
current by the connector the unit is plugged into, or to
reduce the motor current on application of an external
signal such as at standstill.
The external resistor should be selected to give the
required voltage on the current program input of
approximately 0.47 x required current per phase.
Oscillator external controls
Thermal protection (user fit option)
A thermal sensor may be fitted to prevent overheating of
the heatsink and output devices. The sensor should be
a switching type that opens on excessive temperature
such as AIRPAX type 67L080, that operates at 80ºC.
This device may be clipped onto the heatsink bracket
and soldered into the location SW3.
This feature will give a warning on the overtemperature
output, that the heatsink is too hot. This condition may
be latched by setting switch SW1-2 (LT) on. The drive
may be automatically disabled on overtemperature by
setting switch SW1-1 on
The external controls for the oscillator may be
connected via the 32 way DIN41612 connector or
alternatively, if front panel controls are required, may be
connected via a 5 pin MOLEX connector (P3).
+12V
P3-5 or pin 26a
0V
P3-4 or pin 30a
VCO speed i/p
P3-3 or pin 22a
VR2 high speed set
Max
Min
Base speed
High speed
VR1 base
speed set
VCO base speed
P3-2 or pin 24a
close for run
VCO run/stop
P3-1 or pin 24c
MSE570 data sheet
Page 4 of 5
Issue 002
Using the graph below select a value for C-freq for the
chosen pot VR1
Oscillator operation
The normal method of oscillator operation is as follows:
1. The oscillator is started at the base speed by
switching the run switch on with the base/high speed
switch set to base. This base speed is a frequency
offset and should be chosen to be safely within the
pull-in capability of the motor/drive combination, and
ideally above the resonant frequency range. This
base speed is defined by C-freq and the setting of
VR1.
2. The high speed may be selected by switching the
base/high speed switch to high. The oscillator will
then ramp up to the high speed. This high speed is
set by VR2, whose range is defined by R-freq and
C-freq. The ramp rate is determined by the time
constant of R27 (100KΩ) and C-ramp.
3. The oscillator may then be slowed back down to the
base speed by switching the base/high speed back
to base.
4. When the speed has dropped down to the base
setting the oscillator may be inhibited by switching
the run switch off. The motor should only be started,
stopped or have a direction change whilst at the base
speed.
Required base speed (Hz)
VR1=100KΩ
100K
VR1=0Ω
10K
1K
100
VR1=1MΩ
10
1
100p
Max speed/base speed
Base speed
1
0.1
3
The following external components are required to
complete the oscillator:
0 - 1MΩ
1 KΩ
(typ 1 MΩ)
First determine the base speed and the maximum high
speed you wish to obtain.
MSE570 data sheet
10
100
Caution!
The following components need to be soldered onto the
PCB:
IC8
CD4046 CMOS PLL IC (used as VCO)
R-freq
resistor
1KΩ-1MΩ
(typ 5.6KΩ)
C-freq
capacitor >100pF
(typ 10nF)
C-ramp capacitor
(typ 10µF)
P3
optional molex connector if using front panel
controls
pot
pot
1
VR1+10KΩ/R-freq
4
Component selection
VR1
VR2
1µ
100
10
2
10n
100n
C-freq (F)
Then from the ratio of the maximum running speed to
the base speed, use the following graph to select
R-freq.
High speed
1
1n
Page 5 of 5
1. SERIOUS DAMAGE WILL OCCUR if any motor lead
is connected or becomes disconnected whilst the
drive is energised.
2. The drive board should always be mounted such that
the heatsink fins are vertical i.e. with the board on
edge, and adequate clearance be given top and
bottom i.e. 25 mm minimum. When rack mounting
the board there should be at least a 15 mm
clearance between the heatsink and an adjacent
board. If the airflow around the unit is restricted, then
force air cooling should be employed.
3. When using the drive at high ambient temperatures
or at slow speeds or at standstill, whilst at high
current settings, it will prove advantageous to employ
forced air cooling.
4. Motor and power supply connections should be
made with at least 32/0.2 mm wire due to the high
peak currents flowing. All other control wiring may
use 7/0.2 mm.
5. Good engineering practices should be employed in
the commissioning of this product and should be
made to adhere to all relevant regulations.
Issue 002