Delta RMC151 - Manual (Page 1005)

9 Register Reference
• If the Control Output is positive, the Output Deadband (v) is added to the Control
Output.
• If the Control Output is negative, the Output Deadband (v) is subtracted from the
Control Output.
The Output Deadband also works together with the following parameters:
• Deadband Tolerance parameter
If the Position Error is less than the Deadband Tolerance, then only a fraction of the
Control Output, proportional to the Position Error, is applied. This helps keep the axis
from chattering. See the Deadband Tolerance topic for details.
The Deadband Tolerance has no effect in Velocity PID or Velocity I-PD control. The
Deadband Output is applied based on the direction, but always at 100% in one
direction or the other.
• Integrator
The Output Deadband also affects the functionality of the Integral Term. If the target
is stopped and the position error is less than the Deadband Tolerance window or less
than the position corresponding to one half of a transducer Raw Count, then the
integrator is only allowed to wind down. This reduces "hunting". See the Integral Term
and Integral Gain topics for more details.
Determining the Output Deadband
Follow these steps to determine what the Output Deadband should be set to:
1. Give increasing amounts of Control Output to the system with the Direct Output (9)
command until the system starts to move. Start with a Requested Output of 0 V. The
value of Control Output at which the system starts to move is your deadband.
2. If the deadband is less than a few hundred millivolts (approx. 0.4V), your system
probably does not need the deadband eliminator. Set the Output Deadband to 0.
3. If the deadband is greater than a few hundred millivolts (approx. 0.4V), you probably
need the deadband eliminator. Set the Output Deadband to the value of your
deadband.
Control Modes
The Deadband compensation applies to all the closed-loop control modes: Position PID,
Position I-PD, Velocity PID, Velocity I-PD.
Velocity Control
The Output Deadband applies to velocity control axes. If the Deadband Tolerance value is
non-zero, then the Output Deadband will not apply if the Target Pressure or Velocity is
zero. Otherwise, the value of the Deadband Tolerance has no meaning.
Pressure/Force Control
deltamotion.com 985