21.2.2 Setting actuator behaviour on loss of signal
In case of a loss of signal of nominal value E1 or actual value E2, the reac-
tion of the actuator can be programmed via the switch S2-7. The complete
range of choices, however, is only available with signals 4 – 20 mA.
The following reactions are possible:
Fail as is:
Actuator stops immediately and remains in this position.
Fail close
Actuator moves the valve to the end position CLOSED.
Fail open:
Actuator moves the valve to the end position OPEN.
Behaviour on loss of signal of
Prerequisite
1)
Programming
E1
E2
Command signal
Setpoint E1
Feedback
Actual value E2
2)
via DIP switch S2-7
(see figure 48)
fail as is
4 – 20 mA
4 – 20 mA
fail close
4 – 20 mA
4 – 20 mA
0 – 20 mA
0 – 5 V
4 – 20 mA
fail open
4 – 20 mA
4 – 20 mA
4 – 20 mA
0 – 20 mA
0 – 5 V
fail as is
fail open
4 – 20 mA
0 – 5 V
fail close
fail open
4 – 20 mA
0 – 20 mA
0 – 5 V
0 – 20 mA
4 – 20 mA
0 – 20 mA
0 – 5 V
0 – 10 V
0 – 20 mA
0 – 5 V
fail close
fail as is
0 – 20 mA
4 – 20 mA
0 – 10 V
4 – 20 mA
1)
During loss of signal, signals from 0 – 20 mA and 0 – 5 V may be misinterpreted since E1 or E2 (without any fault) can also
be < 4 mA (end position CLOSED = 0 mA or 0 V) when working properly.
2)
Signals for internal feedback:
0/4 – 20 mA from electronic position transmitter or 0 – 5 V from precision potentiometer 5 k
Ω
Table 7: Possible settings (recommended settings are shaded in grey)
37
Multi-turn actuators SA 07.1 – SA 30.1/SAR 07.1 – SAR 30.1
Operation instructions
with actuator controls AUMA MATIC AM 01.1/AM 02.1
