General Description
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Structure of Positioning Controller
WAGO-I/O-SYSTEM 750
I/O Modules
The following must be considered when selecting an appropriate motor:
type of connection and number of phases
required torque progression over speed
required motor current
winding resistance
motor inductance.
The application dictates the torque progression and speed; experience has
shown that a torque margin of approx. 25 %, depending on the mechanical
system properties, is useful. This should be considered when accounting for
any dynamic effects (resonance in mechanical systems).
The positioning process sequences also determine both the average and peak
power supplied to the motor; special attention must be given to the total power
loss and motor temperature.
Depending on the motor model and design, a corresponding current must be
present in order to be transferred from the output stage into the motor. The
required voltage depends on the winding resistance, motor inductance and
speed (anti-EMC). It may be necessary to have considerably higher voltage
levels for the specific current level, particularly at high speeds, than that
specified by the motor data. The manufacturer-provided motor data is based
on motor standstill (ohmic winding resistance). The power output stages for
stepper modules 750-671, -672 and –673 are equipped with power control
systems. For example, it is possible to run 12 V motors with 24 V supply
systems as long as the current, power loss and motor temperature remain
within acceptable limits. Consult the motor manufacturer with any
questions/concerns.
2.1.1.2.4
Mechanical Section
Motor data can be calculated based on the requirements for the load to be
moved, and any additional bearings, transmissions, deflection systems,
damping elements, etc. that may be required. Important parameters here are:
moment of inertia
starting torque
holding torque
torque at the maximum required speed,
cycle times for positioning
requisite acceleration
required torque (where applicable) when passing through mechanical
resonance fields - particularly when mechanical components such as long
drive belts, spring elements or vibration buffers (couplings) are used.
Please note that there must be no step losses if the required mechanical torque
does not exceed the torque supplied by the motor (taking inertia into account).
