Default Speed Setting Control For Newport Stepper Stages; Irms Current Setting For Smc100Pp Controller - Newport SMC100CC User Manual

SMC100CC & SMC100PP
4.0

Default Speed Setting Control for Newport Stepper Stages

(only available for SMC100PP controller)
EDH0206En2042 – 04/16
Due to some technical reasons, all Newport stepper stages will be set to be driven at
reduced speed with the SMC100PP controller (Reduced speed = Nominal speed / 2.5).
In order to check which stages can be driven at reduced speed or full speed, please refer
to the Newport web site (SMC100PP web page).
For example, an URSPP stage with a max speed of 40 °/s will be driven with a max
speed of 16 °/s when controlled by the SMC100PP controller.
For stages than can be driven at full speed (please refer to the Newport web site to get
the list), the defaut speed setting can be increased by the user to get the full nominal
speed.
4.1

Irms Current Setting for SMC100PP Controller

The connection type of a stepper motor can be bipolar (full winding) or unipolar (half
winding), but the SMC100PP controller always controls the stepper motor in the full
winding control mode. So the Irms current in each case must be different each from
other.
In the case of a unipolar motor, if the motor resistance (controlled in half winding) is R,
so the same motor resistance controlled in full winding is 2R.
For the same power (and the same thermal dissipation) in all two cases, we must have:
Here: I is the motor current in the case of half winding control (this is also Asmart:
half
value found in the stage smart EPROM memory).
I is the motor current in the case of full winding control.
full
From (1) we have:
So in the case of a unipolar motor controlled in full winding mode (SMC100PP), the
motor must not be controlled with the Asmart value, but Asmart / √2.
Single-Axis Motion Controller/Driver for DC or Stepper Motor
R.I 2 = 2R.I
half full
I = I / √2
full half
12
2 (1)
(2)