Yokogawa EJX930A - Manual (Page 87)

A1-3
IM 01C25R03-01E
A1.3 Line-segment Factor
Determination Section
When the mode is AUTO and no bit in BLOCK_
ERR is set, the "gradient" and "intercept" of a line
passing through two points that are considered line-
segment approximation values are determined.
A1.3.1 Conditions for Configuring Valid
Coefficients (CURVE_X, CURVE_Y)
No write error is generated with respect to the
settings in CURVE_X and CURVE_Y. However, a
configuration error occurs in the following cases:
1. "+INFINITY" has been configured for X1 or Y1.
2. "–INFINITY" has been configured for each X or
Y.
3. The values of CURVE_X are not increasing in a
monotone manner (X1 < X2 < ... < X20 < X21).
(If SWAP_2 is off, it is acceptable if the values
of CURVE_Y do not increase or decrease in a
monotone manner.)
4. The values of CURVE_Y are not increasing
or decreasing in a monotone manner when
SWAP_2 is on.
If a configuration error occurs, the Block
Configuration Error bit in BLOCK_ERR is set,
causing the mode to change to O/S.
Example of the case where SWAP_2 is off:
Y
Output
Y6
(High limit)
Y1
(Low limit)
X1 X2 X3 X4 X5 X6 X7 =INFINITY
X
Input
FA0103.ai
Figure A1.3 Example of Curve (SWAP_2 = off)
The range of CURVE_X: X1 to X6 (X7 and
above are invalid because "+INFINITY" has been
configured for X7* 1 .)
The X1 to X6 values always increase in a monotone
manner (X1 < X2 < X3 < X4 < X5 < X6).
If an input value is smaller than X1, it is set to Y1.
If an input value is larger than X6, it is set to Y6.
The range of CURVE_Y: Y1 to Y6
It is acceptable if the Y1 to Y6 values do not
increase in a monotone manner.
However, if the setting of SWAP_2 is changed from
off to on, the values of CURVE_Y must increase
or decrease in a monotone manner. Thus, if a
value of CURVE_Y does not increase or decrease
in a monotone manner in this setting, the mode
changes to O/S, causing the Block Configuration
Error bit in BLOCK_ERR to be set.
*1: For any points of the curve that are not used, configure
"+INFINITY" for all of them.
Example of the case where SWAP_2 is on
(monotone increase):
The input range of IN_1 is always in CURVE_X.
The following shows the input/output graph of the
IN_1 values.
Y
Output
Y6
(High limit)
Y1
(Low limit)
X1 X2 X3 X4 X5 X6 X7 =INFINITY
X
Input
FA0104.ai
Figure A1.4 Example of Curve for IN_1
(SWAP_2 = on)
The input range of IN_2 is always in CURVE_Y. The
following shows the input/output graph of the IN_2
values.
Y1
(Low limit)
X6
X5
X4
X3
X2
X1
Y2
Y3
Y4 Y5
Y6
Y7 =INFINITY
Y Input
FA0105.ai
(High limit)
Output
X
Figure A1.5 Example of Curve for IN_2
(SWAP_2 = on)
When SWAP_2 is on, the array elements of
CURVE_Y must be configured for a monotone
increase or decrease. (Y1 < Y2 < Y3 < Y4 < Y5 <
Y6 or Y6 < Y5 < Y4 < Y3 < Y2 < Y1)