DM422 Digital Stepping Drive Manual V1.0
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8
Multiple Drivers
It is recommended to have multiple drivers 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 drivers. Instead, please connect them to power supply separately.
Selecting Supply Voltage
The power MOSFETs inside the DM422 can actually operate within +20 ~ +40VDC, 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 driver 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 ~ +36VDC, leaving room for power fluctuation and
back-EMF.
7. Selecting Microstep Resolution and Driver Output Current
Microstep resolutions and output current are programmable, the former can be set from full-step to
102,400 steps/rev and the latter can be set from 0.3A to 2.2A. See more information about
Microstep
and Output Current Setting
in Section 13.
However, when it’s not in software configured mode, this driver uses a 6-bit DIP switch to set
microstep resolution, and motor operating current, as shown below:
Microstep Resolution Selection
When it’s not in software configured mode, microstep resolution is set by SW5, 6 of the DIP switch
as shown in the following table:
DM422 Digital Stepping Drive Manual V1.0
Toll Free 1-855-435-4958
9
Microstep
Steps/rev.(for 1.8
°
motor)
SW5
SW6
1 to 512
Default/Software configured
ON
ON
8
1600
OFF
ON
16
3200
ON
OFF
32
6400
OFF
OFF
Current Settings
For a given motor, higher driver current will make the motor to output more torque, but at the same
time causes more heating in the motor and driver. 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 driver output current depending on motor phase current, motor leads and connection methods.
Phase current rating supplied by motor manufacturer is important in selecting driver current, however
the selection also depends on leads and connections.
When it’s not in software configured mode, 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
Default/Software configured (0.3 to 2.2A)
ON
ON
ON
0.5A
0.35 A
OFF
ON
ON
0.7A
0.50 A
ON
OFF
ON
1.0A
0.71 A
OFF
OFF
ON
1.3A
0.92 A
ON
ON
OFF
1.6A
1.13 A
OFF
ON
OFF
1.9A
1.34 A
ON
OFF
OFF
2.2A
1.56 A
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.
Web Site: www.helixlinear.com
Web Site:
www.helixlinear.com
