YOKOGAWA FA-M3 VITESSE F3CX04-0N, User Manual

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C2-18
IM 34M06H63-01E 1st Edition : July, 2003-00
If two inputs have different values, switching between the two inputs may result in an
abrupt change in the PV value or a non-continuous PV value. To prevent this, this mode
uses the average of the two inputs to compute the PV value in the overlapping range, as
shown in the formula above. For this to work, however, you must define input 1 and input
2 with overlapping input ranges.
CAUTION
Input 1 must be used for the lower temperature range.

Automatic Changeover Using Upper Limit (SELMD: 1)
In this mode, Input 1 is used when it is not higher than SELH, and Input 2 is used when
Input 1 is higher than SELH, as follows:
Input 1

SELH: Input 1 is selected.
Input 1 > SELH: Input 2 is selected.

Manual Changeover Using Input Selection (SELMD: 2)
Switches between input 1 and input 2 according to the Input Selection (INSEL) parameter,
as follows:
INSEL = 0: Input 1 is selected.
INSEL = 1: Input 2 is selected.
The PV may change abruptly when changeover is made between Input 1 and Input 2, as
illustrated below.
1 0
Input 2
Input 1
PV
INSEL
0
Figure C2.8 Changeover Using Input Selection (INSEL) Parameter