12 HD65 & HD130 STEPPER DRIVES USER GUIDE
Resolution
(with 200 step/rev
motor)
Stepping
Mode DIP Switch
Settings
78
200 steps/revolution Full step ON OFF
400 steps/revolution* Half step OFF OFF
1,000 steps/revolution 1/5 step OFF ON
2,000 steps/revolution** 1/10 step ON ON
* Default resolution setting for HD65/130
** Default resolution setting for HD65/130M
The 1/5 and 1/10 step modes only apply if the optional microstep
card is fitted (types HD65M and HD130M). In a standard drive
(HD65 or HD130) the half-step mode is almost always preferable to
full step, since the slight loss of torque is more than offset by
smoother performance at low speeds.
Standby Current The motor current is automatically reduced at standby; the reduction
depends on the current setting, and is 50% with the drive set to its
full current. At minimum current setting the standby reduction is to
approximately 80% of regulated current.
A larger reduction may be obtained by changing R76 on the drive,
which is normally set at 560 ohms. Reduce the value to reduce the
standby current further. This resistor is located at the bottom of the
PCB opposite the main power supply capacitor, and is accessible
without dismantling the drive. Do not use a value higher than 560R
without consulting Digiplan.
The standby current may be measured by a meter connected in
series with one of the motor leads, or by using an oscilloscope (see
"Test points" on page 14). Note that in modes other than full-step
the current will vary with step position, so it is safest to make the
measurement with the drive on zero phase. Remember to switch off
before disconnecting a motor lead.
Boost Current When boost is applied the motor current increases by approximately
30%. This is set by R77 on the drive and is normally 68K. The
resistor is located next to R76 opposite the power supply capacitor,
and its value may be increased in order to reduce the amount of
boost. Do not use a value lower than 68K.
Anti-resonance
Dropout Speed The anti-resonance circuit is inhibited at speeds above 440 full
steps/sec, and this is determined by R1 on the motherboard. The
standard value is 47K, and halving the resistor value will double the
dropout frequency.