YOKOGAWA F3CU04-0S, Руководство пользователя

Страница: 170 / 260

C3-16
IM 34M06H62-02E 2nd Edition : June 2008-00
C3.11 Two-input Changeover (for use in two-input
changeover mode only)
The two-input changeover function has three modes, which are selected by the
Two-Input Changeover Mode (SELMD) parameter.
Table C3.15 Two-input Changeover Parameters
Data Position Number
Symbol Description Unit Data Range
Default
Value Attribute Stored
Loop 1 Loop 2 Loop 3 Loop 4
361 761 SELMD
Two-input changeover
mode
None
0: Automatic changeover
using temperature range
1: Automatic changeover
using upper limit
2: Manual changeover using
input selection
0 RW 
362 762 SELH
Two-input changeover
upper limit
Industrial
unit
PRL to PRH if SELL <
SELH.
If SELL

SELH,
changeover occurs with
respect to SELH.
PRL+1 RW 
363 763 SELL
Two-input changeover
lower limit
PRL RW 
323 723 INSEL Input selection None
0: Input 1
1: Input 2
0 RW
－

Automatic Changeover Using Temperature Range (SELMD: 0)
In this mode, Input 1 is used when it is below the two-input changeover lower limit
(SELL), Input 2 is used when it is above the two-input changeover upper limit (SELH),
and the average (PV) of Input 1 and Input 2, given by the equation below, is used
between SELL and SELH (overlapping range).
Figure C3.7 illustrates how the PV is selected from Input 1, Input 2 and the average of
Input 1 and Input 2.
PV
Input 1
Input 2
SELH
SELL
PV
Figure C3.7 PV Value in Changeover Mode
- Input 1 must be used for the lower temperature range.
- Input 1 and Input 2 must be defined with overlapping ranges.
CAUTION
2
1
1
1
input
SELL SELH
SELL input
input
SELL SELH
SELL input



 


 












1 PV