MTS Series 793 - Manual (Page 235)

displacement control with a force signal as the limiting input. CLC limits (typically force) limit the amount of
force that can be applied during specimen installation.
Note:
The Station Builder application is used to create CLC control modes.
Access
Station Setup window > navigation pane > Channels CLC control mode > > Adjustments tab
For more information
For more information on how to create and tune a CLC control mode, see How to Create a Channel Limited
Channel (CLC) Control Mode on page 93 and About CLC Tuning on page 236.
Important:
The performance of a CLC control mode is affected by the servo valve’s mechanical balance adjustment.
An unbalanced servo valve can cause a CLC channel to exceed the CLC limit settings. Before attempting
to tune a CLC channel, make sure that the servo valve is properly balanced.
Adjustments Tab - CLC Control Modes
Description Item
Adjusts the gain applied to the active control mode (typically displacement).
The gain settings for the active control mode are usually set to normal Active P Gain
Active I Gain
values and the limiting gain settings are used to optimize the system
response within the CLC bands.
Adjusts the proportional gain applied to the limiting control mode (typically
force). Limiting P Gain is applied only when the force signal is within the
upper and lower limit bands set by the Bandwidth control. Limiting P Gain
Limiting I Gain
Important:
Use the “Limiting P Gain” setting to optimize the CLC system
response. If the actuator responds too slowly, leave the Active gain
settings at normal levels and increase the limiting P Gain to increase
the response.
Sets the CLC control mode’s upper and lower limits (typically force). These
limits define where the CLC bandwidths end. When using Manual Command Upper Limit/ Lower Limit
set to CLC, as the force signal value enters the user-defined CLC band,
channel limiting starts to slow the actuator response. If a force limit is
reached, the limiting channel prevents further actuator movement,
regardless of the displacement command.
To provide a greater range of actuator movement without CLC limiting the
response, only set the limits that will apply to specimen installation. For
example, if you are testing in compression only, set the tension limit to a
high value. For tension testing, set the compression limit to a high value.
Sets the bands in which Limiting P Gain is applied. Bandwidth
• Anytime the limiting signal is within the band, channel limiting is applied.
MTS Series 793 Control Software 235
Station Setup