Emerson E2 Einstein User Manual page 18

ute/seconds by entering "00" for the hour (example:
"00:30:00" for 30 minutes).
• As a time of day in HH:MMx, where x is "a" if the
time is a.m. or "p" if the time is p.m. This is con-
verted to a number of seconds after midnight.
Example: 04:00a is converted to 14400 seconds.
In all cases, time constants are all converted to a num-
ber of seconds when used by the Flex Combiner, so that
mathematical operations like "00:01:00*2" results in 120
(60 seconds multiplied by 2).
In the case of a time constant in HH:MMx format, this
can be used along with the TIME() function to do compar-
isons between the current time and the setpoint. For exam-
ple, IF((TIME()>06:00p)=TRUE,60,50) compares the
current TIME, which returns the time in a number of sec-
onds since midnight, to 06:00p, which is converted to
21600 seconds.
EXAMPLE EQUATIONS: INPUTS AND
CONSTANTS
Equation
AI4+60
(PI*(10M^2))*AI2
AI1+(3DDF*DI2)
Table 2-7
- Equation Examples: Inputs Using Constants
•
2-4 E2 User's Manual Supplement: Flexible Combiner
Description
The value of AI4 plus 60.
Assuming AI2 is a linear
sensor whose output reflects
a water level position in
meters, this equation calcu-
lates the volume of a cylin-
drical tank whose radius is
10 meters. The constant PI is
multiplied by the radius
squared (10M^2) to yield the
circular area of the tank, and
this value is multiplied with
AI2 to yield volume.
Assuming AI1 is a tempera-
ture sensor, this equation
adds three degrees Fahren-
heit to the value of AI1 when
DI2 is ON. Because ON is
equal to 1.0, then 3DDF *1.0
= 3DDF. When DI2 is OFF
(0.0), the expression 3DDF *
0.0 = 0DDF
026-1620 Rev 3 06-JAN-2011