Siemens SIPART DR21 Manual page 76

3 Functional description of the structure switches
3.4 Controller types (S1, S42 to S45)
difference monitoring is possible at all times. At S81 = 7, x1 and w can be displayed on the
digital x/w-display in the levels III and IV. A physical display is possible with Pd, Ad, Ed.
At S81 = 2 or 3, the digital x/w-display can be switched to the external nominal ratio wv
(display level IV). The digital x/w-display indicates the actual ratio xy in display levels I and III.
Switching between wvi and wv
S1 = 1.
The actual ratio is gained by back calculating the ratio formula with the current process vari-
ables x1, x2:
x1-c5
v =
is
x2
= xv (vE -- vA) + vA the result is for xv =
with v
ist
xv is displayed and is required for x-tracking-mode. For the xv-display, x1 and x2 are limited to
+0.5 % so that the display does not become too restless for small x1 and x2 or flip from positive
to negative in the case of negative x2. The linearization of the commanding process variable x2
or the following process variable x1 is possible (S21).
The linearization then acts on the analog displays and the ratio formation and therefore in-
directly on the digital displays for nominal- and actual ratio. The ratio controller has no nominal
ratio limiting because the ratio factor range already marks the limit.
With the Shift key (6) the digital x/w-display can be switched between the display levels I to IV
depending on the position of S81.
In display level II the active nominal ratio wy can be displayed, in dispaly level I/III the actual
ratio xy. The external setpoint wy
nal nominal ratio can also be adjusted.
The active setpoint- and actual value is displayed on the analog displays (see table 3-10).
Structure Posi-
switches tion
S81
[0]
1
2
3
4
5
6
7
Table 3-10 Display levels (S81)
76
takes place in the same way as in the slave controller
E
is displayed in display level IV. The displayed active or exter-
E
Switching the w/x-digital display
Display order
I II
x/xv w/wv
x/xv w/wv x1/xv
x/xv w/wi1/wv
x/xv w/wi1/wv x1/xv
x/xv --
-- w/wv
-- -- x1/xv
xv wv x1
Identification of the displayed variables by the w- or x-signal lamp:
1 = steady light, 0.5 = flashing light, 0 = off
Display order
I II
1 0 0.5 (0 at S81=6)
0 1
v -vA
is
or xv =
vE-vA
Function
III IV
-- --
--
-- wE/wvE/wi2
wE/wvE/wi2
-- --
-- --
--
w
III IV
0
0 0,5
Manual
E
x1-c5
- vA
x2
vE-vA
x-signal lamp
w-signal lamp
SIPART DR21
C73000-B7476-C143-08