Pulse signal: In single pulse (pulse/direction) mode, this input represents pulse
signal, active at each rising or falling edge (set by inside jumper J3); 4-5V
when PUL-HIGH, 0-0.5V when PUL-LOW. In double pulse mode
(pulse/pulse) , this input represents clockwise (CW) pulse,active at high level
or low level (set by inside jumper J3). For reliable response, pulse width
should be longer than 1.5μs. Series connect resistors for current-limiting when
+12V or +24V used.