9.
Failure functions
Definition
Failure functions are started by certain events and lead to a defined action of the
controls or the actuator. A failure operation can be started by a manual action (e.g.
pressing an EMERGENCY stop button). In general, a failure operation is automatically
started by a fault signal from a monitoring function (e.g. loss of signal).
9.1.
Reversing prevention time
Application
Prevention of impermissible operation states such as: Operation command in direction
OPEN, actuator still runs in direction CLOSE due to the delay time.
Properties
The reversing prevention time (off-time between two operation commands in opposite
direction) prevents a restart for a defined interval once the motor has switched off.
Parameters and instructions for setting
Required user level:
AUMA (6)
.
Device configuration M0053
Switchgear M0173
Revers. prevent. time M0174
Default values:
For 3-phase AC motors =
1.0 s
seconds
For 1-phase AC motors =
2.5 s
seconds
Setting range:
0.3 ... 30.0 s
seconds
9.2.
Failure behaviour on loss of signal
Characteristics
The failure behaviour can be used to define AC reaction to loss of signal or a defective
signal.
Only in operation mode Remote will the failure behaviour react to a signal loss. In
operation modes Local or Off, there will be no reaction.
Information
On loss of bus communication, failure operation can only be initiated if the watchdog
function is activated in the master.
As soon as the cause for initiating the failure function is eliminated (connection
restored, master in Operate state), the operation commands from the master can
be executed again at once.
9.2.1.
Failure reaction on loss of signal
Required user level:
Specialist (4)
or higher.
Customer settings M0041
Failure behaviour M0378
Signal loss beh. M0379
Default value:
Good signal first
Setting values:
Good signal first
The <Failure behaviour> is only initiated if the monitored signal fails (falling edge).
This setting ensures that if the signal is missing, the actuator will not start when
switching on (Good signal first).
Immediately active
The <Failure behaviour> is immediately initiated if the monitored signal is missing
(is not present).
84
Actuator controls
Failure functions
ACV 01.2/ACVExC 01.2 Profibus DP
