Numeric Display

Owned by Gary Cane
May 09, 2022


Operator Menu Location: Generic Hardware Operators Displays


Operator Bitmap:


Functional Description:
The Numeric Display generic hardware operator provides access to a numeric display resource in the physical hardware. When the generic operator is linked to a specific hardware resource, it will command that resource to display the value of its input .
Digital input controls the presentation of signal on the display. If , the value will flash on the numeric display; otherwise, if , the value will be shown continuously. Flashing the contents of the numeric display may be useful to indicate particular operating states. For instance, it could be used to indicate that the controller is in Manual mode, or that some alarm condition has arisen.


When multiple generic Numeric Display operators are linked to the same specific hardware resource (e.g., the same physical display), the display will cycle between each operator input value. The digital output y of the operator is HIGH while the physical hardware is currently displaying its input value (e.g., while the operator is active). Digital output y is LOW while the operator is inactive. When a resource is shared between multiple operators, it is a good idea to indicate what value is currently being displayed. This can be done by connecting output y to an LED Display operator. For example, the same physical display can be used to indicate both a process variable and a process setpoint. In the schema diagram below, both process and setpoint values are displayed on the Chameleon PCM-1 top numeric display. The top LED is lit while the process variable is displayed and the second LED is lit when the process setpoint is displayed.


User-Defined Properties:
Object Name. A string label that identifies the operator


Decimal Point Position. The position of the decimal point on the numeric display. The decimal point position can be floating, or it can be fixed after any digit position. It can also indicate that no decimal point is to be displayed. When in floating mode, the decimal point position will depend on the value of input signal . It will display the signal at the maximum resolution possible (using all the available digits).


Brightness. A brightness setting for the LED digits in the range [0-15], with 15 indicating maximum brightness.
Active Period. The period of time (in milliseconds) that the physical display will show input of this operator if the resource is shared. This parameter has no effect if the resource is not shared.


Refresh Rate. The period of time (in milliseconds) between successive display updates while this operator is active.
Display Blinking Input. This property determines if input pin is visible in the schema diagram. Design Pad issues a warning upon processing the schema when the pin is visible but not connected. The warning message is not issued when the pin is not visible (when this property is not checked).


Display Active Output. This property determines if output pin y is visible in the schema diagram.
Pad Leading Zeros. If checked, pads input with leading zeros so that every digit in the display is used. For instance, suppose the linked display has four digits, the operator is configured to not display a decimal point, and the input value . If this property is checked, the display will indicate "0010"; otherwise it will indicate " 10" and the first two digits will be turned off. In this example, if the decimal point position were configured to float, the display would indicate "10.00".


Comments:
•If the numeric display operator is in a sub-schema that is not currently active, its value will not be displayed. If no other operators are linked to that resource, the display is turned off and remains off until the sub-schema is activated.
•If the value of input signal exceeds the capacity of the display (e.g., 9999 for a four-digit numeric displays when the decimal point is floating, or 9.99 for a three-digit display when the decimal point position is set to 'After First Digit'), the displays will show an 'H' in each digit (i.e., "HHHH" on a four-digit display, "HHH" on a three-digit display, etc.).
•If is less than the minimum value for the chosen setting (e.g., -99.9 for a four-digit display with a 'After Second Digit' decimal point position, or -99 for a three-digit display with a floating decimal point), the displays will show an 'L' in each digit (i.e., "LLLL" on a four-digit display, "LLL" on a three-digit display, etc.)

See Also:
LED Display, Bargraph Display