The Analog Change Dialog Box allows users to change the Numeric Values of a Tag (or tag field or BLOCK:PARAMETER) using VIEW. Typically, Setpoints, Valve Outputs, Alarm Limits are analog data.
The design of the Dialog Boxes allows users to enter Data using a Mouse, Touch Panel or Keyboard.
Figure 9-22Analog Change Dialog Box
Tag name is shown in the Title Bar (OUT-184 in the example)
Current Numeric Value (12.00)
Engineering Units ( PSI in the example) See 4.2.27 for more on Eng Units.
Ramp Keys ramp the value of the tag by holding the key. Single arrow is slow, the double arrows are fast. If Hold Output is selected Changes are not sent to tag until ENTER is pressed. Otherwise, changes are made instantly can continuously if Hold Output is not selected.
Slider Bar allows users to "Drag" the bar by clicking with the mouse and holding the mouse key down while moving the mouse. If Hold Output is selected Changes are not sent to tag until ENTER is pressed. Otherwise, changes are made instantly can continuously if Hold Output is not selected.
Output Limits (High Output and Low Output Limits).These are the values configured by the engineering when configuring ht tag. By default, these are the same a Span High and Span Low.
Exit - Closes the dialog box without sending the value to the Tag.
Enter - Sends the numeric value to the tag. If Hold Output is selected, this closes the Change Dialog Box.
Hold Output - if the button is depressed, no changes are made until the Enter Key is pressed. This "Holds" and "Output" until the operator has a chance to review the number and confirm the change by pressing ENTER.
This implements a two step process to prevent accidental changes in values to tags. Hold Output is the default.
Backspace - erase key intended for use with touch panels.
Numeric Keypad - uses the mouse or touch screen to enter numbers. The keyboard can also be used to enter numbers. (ABCDEF are for HEX)
Figure 9-23Numeric Key Pad - Change Dialog Box
Number Format changes the base of how the number is displayed.
Figure 9-24Number Format - Change Dialog Box
Dec - Decimal , base 10 (0 - 10), the way most people think of numbers.
Hex - Hexadecimal, base 16 (0-F)
Bin - Binary (1 and zeroes only)
Oct - Octal, base 8 (0 - 8)
For example, 12.00 in Decimal = C in Hex
12.00 in Decimal = 1100 in Binary
12.00 in Decimal = 14 in Octal
Engineers and Technicians can create RAMP Pushbuttons on Graphic Displays that will change the value of a an Analog Tag without opening the Change Dialog Box using the <SETVAL> keymacro. However, the pushbutton may bypass security of the tag and will not open the Password Dialog Box, if the user does not have the required security area and level to change the tag .