Emerson FIELDVUE DVC6200f Instruction Manual page 161

Y
100%
(X
11
0%
(X
12
0%
Table 4-46. OUT_ARRAY Coordinates
Index Coordinate
− Value of OUT_1 at X
0 Y
11
− Value of OUT_1 at X
1 Y
12
− Value of OUT_2 at X
2 Y
21
− Value of OUT_2 at X
3 Y
22
A configuration error is set in BLOCK_ERR and the
actual mode of the block goes to Out of Service if the
X values have any of the following conditions: X
X , X < = X , X < = X
11 12 11 22
Refer to figure 4-19 for an example of LOCKVAL =
true, and figure 4-20 for an example of LOCKVAL =
false. The parameter LOCKVAL provides an option to
specify whether OUT_1 remains at its ending level
when control is switched to OUT_2, or goes to Y
LOCKVAL is true, OUT_1 remains at its ending value
when X is greater than X
12
OUT_1 goes to Y when X is greater than X
11
OUT 1
0%
100%
50%
SP
Figure 4-19. OUT with LOCKVAL True
November 2010
Split Range
(X22 , Y22)
, Y )
11
OUT_1
OUT_2
(X , Y )
, Y )
21 21
12
50% 100%
SP
Figure 4-18. Split Range and Sequence Operation
11
12
21
22
<
21
.
21
. If
11
. If LOCKVAL is false, then
.
12
OUT 1 remains at
end point when OUT_2
is non-zero
OUT 2
OS Function Block
Sequencing
Y
(X
100%
OUT_1
0%
(X , Y )
11 11
X
0% 50%
SP
OUT 1
0%
50%
100%
SP
Figure 4-20. OUT with LOCKVAL False
Some hysteresis in the switching point may be
required because the output may change by a full
stroke of the valve. HYSTVAL [12] contains the
amount of hysteresis. If X < = X12−HYSTVAL,
OUT_1 may be determined by the calculated y value.
If X12−HYSTVAL < X < X12 and X has not reached
X12 since it was less than X12−HYSTVAL, OUT_1
may be determined by the calculated y value. If
X12−HYSTVAL < X < X12 and X has reached X12
since it was less than X12−HYSTVAL, OUT_1 may be
determined by the LOCKVAL setting. If X12 < X,
OUT_1 may be determined by the LOCKVAL setting.
Initialization and Back Calculation
Requirements
Refer to figure 4-21, Output Splitter Configuration,
where:
PID1 = Upstream driving controller or function block.
, Y ) (X , Y )
12 12 22 22
OUT_2
(X , Y )
21 21
X
100%
OUT 2
OUT_1 goes to zero
OUT_2 becomes
149
4