Auto_Manual (A_M) Menu System (FAC2100)

Owned by Gary Cane
Last updated: Jun 30, 2014 by Mark Krueger (Unlicensed)

Auto/Manual (A/M) Menu System 

A typical process controller may operate in automatic mode (where the device computes a controller output) or in manual mode (where a plant operator specifies the controller output). The FAC-2100 unit is a versatile multi-loop controller that provides this functionality and more. It can be configured to operate in a partially-manual, partially-automatic mode called mixed mode. While in mixed mode, a subset (e.g., an individual loop) of the control scheme executed by the device may operate in automatic mode, while another subset operates in manual mode, while yet another subset operates in automatic mode. (For instance, in a three-loop control scheme, the plant operator may maintain two loops in automatic modes and the third in manual mode.)


The FAC-2100 contains an A/M Menu system that presents a plant operator with a list of all control signals that may be toggled between automatic and manual modes. The menu system also allows the operator to set the controller output signal value when in manual mode. A control signal object in the A/M Menu system is equivalent to the circuit shown in the figure below. The figure shows an input signal and an adjustable signal generator connected to a switch. The output of the switch is attached to the output of the circuit. When the switch connects the input signal to the output signal, the switch is said to be in the automatic position. The switch is in the manual position when the signal generator is connected to the output of the switch. If the switch is in the manual position, adjusting the level of the signal generator can set the output. The FAC-2100 provides the control engineer with both stand-alone A/M circuits and A/M circuits built into controller blocks (e.g., PID, PD, and PI operators). See the Design Pad Operators Reference instructional bulletin (Fairmount Automation Technical Bulletin PDG-TR-2011/13) for more information.

Typical 'A/M' menu object

 

Notice that in order to adjust a typical A/M menu object, the user must be able to change both the switch position and the signal generator output level.


The A/M Menu system is accessed via the A/M button on the FAC-2100's front panel; manual signal adjustments are made with the LEFT and RIGHT arrow buttons (refer to The Front Panel). The flow chart below describes how these buttons are used to operate the A/M Menu system. When a control program contains a single A/M circuit (the usual configuration) adjustments are made as follows:

  1. Press the A/M button to enter the Auto-Manual Menu system. The single A/M circuit will be switched into manual mode.
  2. Edit the manual output by pressing the LEFT and RIGHT arrow buttons. If an arrow button is held down, the output value will begin to change at a rapid rate (note: the repeat rate for a held key is adjustable in software.)
  3. To return the system to automatic mode, press the A/M button again.


When the SET menu is active, the status and adjustment value for the A/M Menu system are indicated on the bottom alphanumeric display line. Otherwise they are indicated on the top two alphanumeric display lines.


When a control program contains multiple A/M circuits, adjustments are made as follows:

  1. Press the A/M button to enter the Auto-Manual Menu system.
  2. The top two lines All user-defined alphanumeric text messages on the top two display lines are paused while the controller is in the auto-manual menu system. of the alphanumeric display present a list of A/M circuit names (such as 'water level' or 'temperature') that can be adjusted. Use the LEFT and RIGHT arrow buttons to scroll through the list until the desired name to be changed is displayed.
  3. If you wish to exit the A/M Menu system, scroll through the list until the 'Press A/M to exit A/M menu' message is displayed and press the A/M button.
  4. A/M Mode is controlled as follows:
    1. To switch a selected A/M circuit from automatic mode to manual mode, press the A/M button and go to step 5.
    2. To switch a selected A/M circuit from manual mode to automatic mode, press and hold the A/M button for more than two seconds and go to step 2.
    3. To adjust the generator signal of a selected A/M circuit which is already in manual mode, press and hold the A/M button for less than two seconds and go to step 5.
  5. Adjust the manual output by pressing the LEFT and RIGHT arrow buttons. If an arrow button is held down, the parameter value will begin to change at a rapid rate (note: the repeat rate for a held key is adjustable in software.)
  6. When the desired value has been reached, press the A/M button to record the change. Note that the A/M circuit will remain in manual mode. Go to step 3.


If the control schema has multiple A/M circuits, you may not enter both the SET and A/M menus simultaneously. Exit out of one menu before attempting to enter the other.

A/M Menu System Flow Chart

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