CPU Controls and Displays
Original instructions
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Lens Cover
The protective lens cover (2 on the CPU front panel) can be opened by sliding it upwards.
With the lens cover open you have access to the following items:
Key Switch
The key switch (4) is a security feature and a memory protection switch. The key switch has two positions: locked and unlocked. The key switch is only read and deciphered by the PLC OS portion of the firmware and not by the OS loader portion.
The Quantum processors have a set of system menus that enable the operator to:
The key positions are shown in the table below:
Key Position
PLC Operation
unlocked:
  • System menu operations can be invoked and module parameters can be modified by the operator with the LCD and keypad.
  • Memory protection is OFF.
  • You can switch to Maintenance mode (in Safety processors).
locked:
  • No system menu operations can be invoked and module parameters are read-only.
  • Memory protection is ON.
  • Safe mode forced (in Safety processors).
Switching the key switch position from locked to unlocked or vice versa turns on the LCD's backlight.
NOTE: For more explanations about Maintenance and Safe modes, refer to the Modicon Quantum, Quantum Safety PLC, Safety Reference Manual.
Key Switch Description Tables
The following table provides information on switch position for high end Quantum 140 CPU 6•• ••• with firmware < 3.12:
Operation
Switch Position
Unlocked
Locked
Programming mode
Allowed
Allowed
Monitoring mode
Allowed
Allowed
Upload application
Allowed
Allowed
Download, online modification
Allowed
Forbidden
Stop/Run/Init commands from Control Expert
Allowed
Allowed
Unity Pro is the former name of Control Expert for version 13.1 or earlier.
The following table provides information on switch position for high end Quantum 140 CPU 6•• ••• with firmware ≥ 3.12 and Unity Pro < V8:
Operation
Switch Position
Unlocked
Locked
Programming mode
Allowed
Forbidden
Monitoring mode
Allowed
Allowed
Upload application
Allowed
Forbidden
Download, online modification
Allowed
Forbidden
Stop/Run/Init commands from Unity Pro
Allowed
Forbidden
Unity Pro is the former name of Control Expert for version 13.1 or earlier.
The following table provides information on switch position for high end Quantum 140 CPU 6•• ••• with firmware ≥ 3.2 and Unity Pro ≥ V8:
Operation
Switch Position
Unlocked
Locked
Programming mode
Allowed(1)
Forbidden
Monitoring mode
Allowed(1)
Allowed(1)
Upload application
Allowed(1)
Forbidden
Download, online modification
Allowed(1)
Forbidden
Stop/Run/Init commands from Control Expert/UnityPro
Allowed(1)
Forbidden
(1): Password-protected if a password has been defined in the Control Expert/Unity Pro application
Reset Button
Pressing the reset button (12) forces a cold start of the PLC.
LCD Display
The liquid crystal display (LCD - 3) has 2 lines with 16 characters each with changeable backlight state and contrast:
The backlight handling is entirely automated to save the life of the LCDs. The backlight turns on when one of the following occurs:
The backlight stays on for error messages as long as the error message is displayed otherwise, the backlight automatically turns off after five minutes.
Adjusting the Contrast
The contrast is adjustable from the keypad when the default screen is displayed:
Step
Action
1
Press the MOD key:
2
To adjust the contrast darker press:
3
To adjust the contrast lighter press:
4
To confirm the setting press:
Keypad
The keypad (5) has five keys that are mapped to hardware addresses. Each of the two arrow keys includes an LED: 
1
5 keys 
2
2 LEDs
Using the Keys
Keypad functions:
Key
Function
To cancel an entry, suspend or stop an action in progress
To display the preceding screens successively (move up the menu tree)
To confirm a selection or an entry
To set a field on the display into the modify mode
LED: on
Key active:
  • to scroll through menu options
  • to scroll through modify mode field options
LED: flashing
Key active: The modify mode field can be scrolled.
LED: off
Key inactive: No menu options and no field options.
LED on
Key active:
  • to move around in a screen, field to field
  • to go to the sub-menu
LED flashing
Key active: Used to move digit to digit in a modify mode field.
LED off
Key inactive, there is no:
  • sub-menu for menu option
  • scrolling around a screen
  • scrolling around a field