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MCT-CM
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The Low Setpoint and High Setpoint fields are used to set the minimum and maximum allowable set points
for the control loop. These settings allow the OEM to enter an absolute minimum and maximum range for the
operation of the control loop regardless of the end user’s desired range. The set point “Limits” screen in the
runtime application (see section 9.4 Limits) will be limited to the loop input low and high set point limits as set
in the configurator. The end user will be able to decrease the set point range if given access in the runtime
application, but not increase the range beyond these limits.
NOTE: If the low and/or high set point limit fields exceed the range of the loop control input, a communications
error will result when the MCT runtime application is started. This error will not be able to be cleared
and the loop will not operate properly until these low and high set point limit fields are set to a value
within the input range of the controller.
4.2.2 Loop Options
The MCT provides additional control options for each control loop. These options are accessed by pressing
the
“Options” button on the Loop Settings screen.
4.2.2.1 Loop Permissives
By default, the MCT is the master control for the system. All loop set points, auto/manual and auto tune
functions are controlled by the MCT. If a user tries to modify any of these settings through the front panel of
the loop control, their selections will be overridden by the MCT. If there is a desire to allow a user to adjust
these settings from the front panel of the loop control as well as the MCT interface, the loop permissions can
be set to allow the user to adjust each of the individual settings at the loop control.
NOTE: The security suite of the MCT runtime application provides audit trail capabilities in which all user
changes to the system are tracked and logged. This includes user set point, auto/manual and auto
tune changes to each individual loop control attached to the system. If loop permission is granted
for one or all of these settings, the user will be able to make adjustments at the loop controller.
These changes cannot be tracked or controlled by the MCT security settings as they were made at
the loop control, not the MCT interface. If the application requires the user to have proper security
rights to make any control system changes, the loop permissions should not be enabled unless other
means are used to prevent adjustments at the loop controller without proper security access to the
loop controller.