RM42A Digital Stepper Drive User Manual
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6.2 Selecting Supply Voltage
The RM42A is designed to operate within 18 - 50VDC 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.
7. DIP Switch Configurations
The RM42A has one 8-bit DIP switch and one 1-bit selector.
The first 8-bit is used to configure settings of micro step
resolution, output current, motor standstill current, pulse type and smoothing time as shown below.
SW1
SW2
SW3
SW4
SW5
SW6
SW7
SW8
The second 1-bit selector is located on the top (S2 in figure 2), used to configure the voltage of control signals. For the
safety of optically coupled, the factory setting is 24V,
which no need to connect 2K resistors like the old drives, making
it easier to use. When the voltage of the control signal is 5V, the S2 must be set to 5V, otherwise, the motor won't work
.
7.1 Microstep Resolution Configurations
Microstep resolution is set by SW5, 6, 7, 8 of the DIP switches
as shown in the following table.
Note: “default” means
the parameters can be set by software.
Microstep
Steps/rev.(for 1.8°motor)
SW5
SW6
SW7
SW8
1
200 (default)
ON
ON
ON
ON
2
400
OFF
ON
ON
ON
4
800
ON
OFF
ON
ON
8
1600
OFF
OFF
ON
ON
16
3200
ON
ON
OFF
ON
32
6400
OFF
ON
OFF
ON
64
12800
ON
OFF
OFF
ON
128
25600
OFF
OFF
OFF
ON
5
1000
ON
ON
ON
OFF
10
2000
OFF
ON
ON
OFF
20
4000
ON
OFF
ON
OFF
25
5000
OFF
OFF
ON
OFF
40
8000
ON
ON
OFF
OFF
50
10000
OFF
ON
OFF
OFF
100
20000
ON
OFF
OFF
OFF
125
25000
OFF
OFF
OFF
OFF
Idle Current
Output Current
Microstep
