EM870S Digital Stepper Drive User Manual
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4. Control Signal and Fault Output
4.1 Control Signal Connection
The EM870S can accept differential or single-ended control signals (pulse, direction, and enable) in open-collector or
PNP connection through the P1 connector (figure 2). It is recommend to add an EMI line filter between the power
supply and the drive to increase noise immunity for the drive in interference environments.
Figure 3
Connections to open-collector signals
Figure 4
Connections to PNP signals
(Common-anode)
(Common-cathode)
4.2 Fault and Brake Output Connection
Fault Output
When over voltage or over current protection happens, EM870S red status LED light will blink and the impedance
state between ALM and COM- will change (from low to high or high to low depending on configuration) and can thus
be detected. Fault output connection is optional, and it can be connected either in sinking or sourcing.
Figure 5
Sinking output
Figure 6
Sourcing output
Brake Control
It is recommended to connect a fly-wheel diode in parallel to a 24VDC relay and brake coil connection. Refer to the
following figure for brake connection.