Using the Transmitter
7.3Viewing process variables
Process variables include measurements such as mass flow rate, volume flow rate, mass total, volume total, temperature, and density.
You can view process variables with the display (if your transmitter has a display), ProLink II, or a DeviceNet tool.
Note: If the petroleum measurement application is enabled, two of the API process variables are
averages: Batch Weighted Average Density and Batch Weighted Average Temperature. For both of these, the averages are calculated for the current totalizer period, i.e., since the last reset of the API volume totalizer.
7.3.1With the display
By default, the display shows the mass flow rate, mass total, volume flow rate, volume total, temperature, density, and drive gain. If desired, you can configure the display to show other process variables. See Section 8.9.5.
The LCD panel reports the abbreviated name of the process variable (e.g., DENS for density), the current value of that process variable, and the associated unit of measure (e.g., G/CM3). See Appendix D for information on the codes and abbreviations used for display variables.
To view a process variable with the display:
•If Auto Scroll is enabled, wait until the desired process variable appears on the LCD panel.
•If Auto Scroll is not enabled, Scroll until the name of the desired process variable either:
-Appears on the process variable line, or
-Begins to alternate with the units of measure
See Figure
The display precision can be configured separately for each process variable (see Section 8.9.5). This affects only the value shown on the display, and does not affect the actual value as reported by the transmitter via digital communications.
Process variable values are displayed using either standard decimal notation or exponential notation:
•Values smaller than 100,000,000 are displayed in decimal notation (e.g., 1234567.89).
•Values greater than 100,000,000 are displayed using exponential notation (e.g., 1.000E08).
-If the value is less than the precision configured for that process variable, the value is displayed as 0 (i.e., there is no exponential notation for fractional numbers).
-If the value is too large to be displayed with the configured precision, the displayed precision is reduced (i.e., the decimal point is shifted to the right) as required so that the value can be displayed.
7.3.2With ProLink II
The Process Variables window opens automatically when you first connect to the transmitter. This window displays current values for the standard process variables (mass, volume, density, temperature, external pressure, and external temperature).
To view the standard process variables with ProLink II, if you have closed the Process Variables window, click ProLink > Process Variables.
To view API process variables (if the petroleum measurement application is enabled), click ProLink > API Process Variables.
36 | Micro Motion® Model 2400S Transmitters for DeviceNet™ |
