Anaheim Bilevel Step Motor Driver BLD72 - Manual (Page 3)

3
Clock Modes
The BLD72 has two clock options: Clock and Direction, or Dual Clock operation. Jumper JP2 is used to
select the clock option. Basically JP2 selects Terminal 5 as either the Direction input or the CCW input.
With the Clock and Direction option (most common option), clock pulses applied to the Clock input (Ter-
minal 6) cause the motor to step. The direction of the motor is determined by the logic level of the Direction
input (Terminal 5). Jumper JP2 must be in the “2-3” position for this mode (see Figure 4 and Table 1).
Physical direction also depends on the motor wiring.
With the Dual Clock option, clock pulses applied to the Clock input (Terminal 6) cause the motor to step in
the clockwise direction. Clock pulses applied to the CCW input (Terminal 5) cause the motor to step in the
counterclockwise direction. Jumper JP2 must be in the “1-2” position for this mode.
Either positive or negative going pulses may be used by setting jumpers in the appropriate position (see
Table 1). To determine which setting to use, first consider the type of clock pulse output on the pulse
generator or indexer (controller). If the clock output on the controller is open-collector type (sinking), then
use the negative going jumper setting. If the clock output on the controller is a pnp or p-channel (sourcing)
type, then use the positive going jumper setting. If the clock output on the controller is a TTL/CMOS type
(totem pole), then either setting will work; but the jumper setting should be chosen based on the level of
the clock output when the controller is not pulsing. If the clock is low when not pulsing, then use positive
going jumper settings. If the clock is high when not pulsing, then use the negative going jumper setting.
The clock inputs (Clock and CCW) are pulled up to +5Vdc through a 10K ohm resistor for negative going
clock inputs; or pulled down to 0VDC through a 10K ohm resistor for positive going clock inputs. The
pullups/pulldowns are followed by an RC filter. See Figure 2 and Figure 3.
Motor On/Off Input
The motor on/off input allows de-energizing a motor without disturbing the positioning logic. After reener-
gizing the motor, a routine can continue. This reduces motor heating and conserves power, especially in
applications where motors are stopped for long periods and no holding torque is required. If holding torque
is required (such as when lifting a load vertically), then the motor must stay energized.
Figure 2: Sourcing Clock Input
Figure 3: Sinking Clock Input