General Software Information - MTS Systems Level Plus Operation And Installation Manual

2

General Software Information

Advanced software techniques and concurrent operations are used to provide minimum scan
times and optimum overall system performance. The SCAN processor runs in background mode
scanning each gauge for level and temperature information. Temperature scans occur once per
five level scans. In addition, the scan processor performs level, temperature, and volume calcula-
tions; alarm processing; and maintenance of the active data arrays. The DISPLAY processor is a
foreground operation that transfers the array data to the LCD display. The DISPLAY processor
runs under keypad control allowing the user to alter the scan sequence and the type of data
being displayed. The COMMUNICATION processor is another background operation that handles
all external host communications to the Level Plus monitor. All three operations run independent-
ly, allowing immediate access to the data array with no additional over-head imposed on the
SCAN processor; thereby, minimizing scan rates and alarm response times. See Figure 2.
In addition to the advanced processing environment offered by the Level Plus system, the soft-
ware also supports a high degree of programmability, allowing the user to configure the system
to satisfy particular needs. The programming software is user friendly and allows the user to alter
many system parameters. Where possible, the software provides error checking on data entered
by the user. The software checks for valid assignments and erroneously entered data values. If the
software receives an illegal assignment or erroneous value, the entered parameter is rejected and
the user is prompted to reenter the correct value. The programmable parameters are described in
the following pages.
2
ASYNCHRONOUS
COMMUNICATION
PORT
Figure 2. Level Plus DDA Monitor Software Structure
Display Update Rate
The display update rate is programmable from 1 to 25 seconds. This parameter affects
only the display update rate and does not affect the data acquisition scan rate. The soft-
ware also supports scan override and scan hold functions.
LCD Contrast Ratio
The Level Plus monitor uses a LED backlit, top-view LCD display module. The software
allows the user to adjust the optimum contrast ratio (viewing angle).
P
R
O
S
C
C
E
DATA
A
S
N
ARRAYS
S
O
R
I/O
PROCESSOR
RELAY 4-20
OUTPUTS OUTPUTS
P
D
R LCD
I
O
DISPLAY
S
C
P
E
L
S
A
S
Y KEYPAD
O
R