Siemens SIPART PS2 6DR5020 Series Manual page 82

Operation
y = x
100 %
0 %
100 %- -SPRE
Figure 4-7 Example: Split range-operation with two positioners
10.TSUP
11.TSDO
12.SFCT
82
Positioner 1
6.SDIR = FALL
Total setting range
100 %- -SPRA
Positioner 1
Setting range 1
Setpoint ramp UP
and
Setpoint ramp DOWN
The setpoint ramp is effective in automatic operation and limits the
speed of alteration of the active setpoint. When switching over from
manual operation to automatic the active setpoint is adjusted to the set-
point on the positioner with the setpoint ramp.
This bumpless manual/automatic switchover avoids excessive pressure
increases on long pipelines.
In the position TSUP = Auto the slower of the two travel times determi-
ned during initialization is used for the setpoint ramp. TSDO is then in-
effective.
Setpoint function (see figure 4-8, page 83)
Non--linear valve characteristics can be linearized with this function and
any flow characteristics simulated in linear valve characteristics.
Six valve characteristics are stored in the positioner
- equal percentage
- equal percentage
- equal percentage
- inverse equal percentage
Positioner 2
6.SDIR = riSE
SPRA SPRE
Positioner 2
Setting range 2
1 : 25 (12.SFCT = 1 -- 25)
1 : 33 (12.SFCT = 1 --33)
1 : 50 (12.SFCT = 1 --50)
1 : 25 (12.SFCT = n1 -- 25)
100 %
J
W
[0 % to 100 %]
SIPART PS2 Manual
A5E00074631-01