Technical Specifications

ValVue Digital Communications Software Ver. 2.80
580
GE Oil & Gas
Initial Setpoint When power is applied to the SVI after being off longer than three
seconds the SVI performs a cold start where its memory is restored
from parameters stored in non-volatile memory. This parameter
determines the setpoint if the startup mode is local. Local setpoints
are entered in process variable units. lithe SVI is in ratio control
mode, these units may be different from the setpoint units.
Controller Period The controller can process the setpoint and process variable data
every 0.15 seconds (6.7 times per second) to 10 seconds. At 0.15 sec-
onds the display and button response is degraded. For fast pro-
cesses, a rate of 0.2 would be a reasonable value and for slow
processes 2 seconds is common.
Ratio Control This option turns ratio control on or off. In ratio control, the setpoint
and process variable may be in different engineering units or on dif-
ferent scales. The relationship between the setpoint in process vari-
able units and the raw setpoint is given by:
Setpoint (in process variable units)=Ratio Gain x Setpoint +Ratio Bias.
The setpoint in process variable units is used in the PID calculation to
compute error.
PV Units Code / Remote SP
Units Code
You can select the units for the process variable and setpoint. HART
defines units codes for many commonly used units. The AMS
snap-on is programmed to recognize many of these and you can
select them from the list box. If the units used is not in the list box,
enter the HART units code in the list box. In which case the program
only reports the code, not the text version of the units.
Menu -Controller Configuration
When the user right-clicks on the Controller Configuration tab, a context menu appears. The
following items may be on the menu (the items that appear depend on the SVI mode).
 Report Setup -Allows the user to select a report file and a report printing program.
 Report-Generates a report of the SVI parameters.
 Detach Trend- Removes the trend display from the tabbed dialog and creates a
separate trend display.
 Help-Displays the help file at the Controller Monitor tab instructions.