DMD870 Digital Stepper Drive User’s Manual
Motion Control Products Ltd.
P a g e
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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.
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
(0.5 to 7.0A)
OFF
OFF
OFF
2.6A
1.8A
ON
OFF
OFF
3.4A
2.4A
OFF
ON
OFF
4.0A
2.8A
ON
ON
OFF
4.8A
3.4A
OFF
OFF
ON
5.4A
3.8A
ON
OFF
ON
6.1A
4.3A
OFF
ON
ON
7.0A
5.0A
ON
ON
ON
Notes:
Due to motor inductance, the actual current in the coil may be smaller than the dynamic
current setting, particularly under high speed condition.