Gain Sets Overview

Most control applications require only one set of gains that never change. However, some applications may require different gains at different times. For example, a press may switch from a large valve to a small valve, or an application may require different gains for Position I-PD and Velocity I-PD control modes. The Gain Sets provides a method of storing two separate sets of gains and applying those gains as needed.

Each position or velocity axis can have two gain sets. The RMC applies the gains from one of the sets according to the selected option of the Gain Sets axis parameter, listed in the table below. The Current Gain Set axis status register displays the currently applied gain set.

Gain Set Option	Description
Single (default)	Only one gain set is available. This option is the best choice for most applications.
Dual (RMC200 only)	Two gain sets are available. Use the Select Gain Set (75) to switch between gain sets. The axis will use gain set #0 when the RMC powers up.
Pos, Vel	Automatically chooses a gain set based on position or velocity control. Gain Set#0 applies when the Current Control Mode is Position PID or Position I-PD. Gain Set#1 applies when the Current Control Mode is Velocity PID or Velocity I-PD.
PID, I-PD	Automatically chooses a gain set based on PID or I-PD control. Gain Set#0 applies when the Current Control Mode is Position PID or Velocity PID. Gain Set#1 applies when the Current Control Mode is Position I-PD or Velocity I-PD.

Notice that using velocity or I-PD control does not necessarily require using dual gain sets. If you have a single gain set, that set will always be used for the position or velocity control, whether it be PID or I-PD. If you will be using both position and velocity or both PID and I-PD on the same axis, the gain sets will be useful to you.

The Symmetrical/Ratioed parameter always applies to both gain sets.

The Gains Sets feature is related to, but distinct from, ratioed gains in the forward and reverse direction of motion on asymmetrical systems, and gain scheduling, where the gain values are continuously modified based on the state of the system.

Choosing a Gain Set Option

To set the Gain Set option, use the Gain Sets parameter. This parameter is located in the Axis Tools, Axis Parameters pane, on the All tab, in the Position/Velocity Control section.

After choosing an option other than Single, two gain sets will appear. The tuning tools will always apply to Gain Set 0. You can tune up the axis using the Tuning Tools, then copy the gains to gain set 1.