EM870S Digital Stepper Drive User Manual
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switch position to OFF for normal operation.
8. Wiring Notes
In order to improve anti-interference performance of the drive, it is recommended to use twisted pair shield cable.
To prevent noise incurred in PUL/DIR signal, pulse/direction signal wires and motor wires should not be tied up
together. It is better to separate them by at least 10 cm; otherwise the disturbing signals generated by motor will
easily disturb pulse direction signals, causing motor position error, system instability and other failures.
If only one power supply serves multiple EM870S drives, separately connecting the drives to the power supply is
recommended instead of daisy-chaining.
It is prohibited to pull and plug connector P3&P4 while the drive is powered ON, because there is high current
flowing through motor coils (even when motor is at standstill). Pulling or plugging connector P4 with power on
will cause extremely high back-EMF voltage surge, which may damage the drive.
9. Typical Connection
A complete stepping system should include stepping motor, stepping drive, power supply and controller (pulse
generator). A typical connection is shown as figure 12.
Figure 12
Typical connection
10. Sequence Chart of Control Signals
In order to avoid some fault operations and deviations, PUL, DIR and ENA should abide by some rules, shown as
following diagram: