Cashco Siemens PS2 I/P - Manual (Page 16)

Design and Functional Principle
16
SIPART PS2 Manual
A5E00074631-01
puts respond even when the power supply fails or the electronics are
defective.
The actuator can also be blocked or driven to its final positions depen-
ding on the configuration for example by an external event via a digital
input (DI2) on the alarm module.
If you require electrically independent limit value messages from the
standard controller, you will have to use the SIA module with the slot
initiators instead of the alarm module.
Communication with the controller is possible via the optional HART
interface.
2.2 Instrument Components
O
90
O
33
3 14
90°
33°
4
2
1
15
5 6
6.1 6.2
7 8 9 10 11
12
13
4...20
m
A
0/4...20
m
A
3/4 W 2 W
DI1
1 Input: Supply air 7 Silencer
2 Output: Actuating pressure Y1 8 Transmission ratio selector
3 Display 9 Adjusting wheel slip clutch
4 Output: Actuating pressure Y2 *) 10 Terminals options modules
5 Operating keys 12 Dummy plug
6 Restrictor 13 Screw--type cable gland
6.1 Restrictor Y1 14 Terminal plate on cover
6.2 Restrictor Y2 *) 15 Purging air switch
*) in double--acting actuators
Figure 2-1 View of the positioner in normal version (cover open)