X-DO 24 01
4 Start-up
HI 801 019 E Rev. 4.00
Page 33 of 52
4.3
Line monitoring (SC/OC)
Line monitoring consists of monitoring for both short-circuits and open-circuits (SC/OC
monitoring) and can be configured for each channel. The switching thresholds for line
monitoring are predefined (see Table 8)
The following points must be taken into account for line monitoring (SC/OC):
Line monitoring reliably detects an open-circuit (OC) if a load with current input of at
least 10 mA is connected.
If an actuator is redundantly connected to two modules, line monitoring reliably detects
an open-circuit (OC) if a load with current input of at least 20 mA is connected.
Line monitoring reliably detects a short-circuit (SC) when currents exceed 0.8 A.
If an actuator is redundantly connected to two modules, line monitoring reliably detects a
short-circuit (SC) when currents exceed 1.6 A.
Line monitoring (OC/SC) can be configured for each channel as follows:
In
the
I/O Submodule DO24_01
tab, adopt the setting
SC/OC Interval
(
≥
40 ms
) for all
channels
In
the
I/O Submodule DO24_01: Channels
, activate
SC/OC active
,
Default setting: Activated
In
the
I/O Submodule DO24_01: Channels
,
max. Test Pulse Duration
0 µs...50 ms,
if
SC/OC active
(
activated
)
4.3.1
Recommended Values for Line Monitoring
Test Impulse Duration
SC/OC Interval
Relationship
200 µs
40 ms
0.5 %
1 ms
200 ms
0.5 %
10 ms
2 s
0.5 %
20 ms
4 s
0.5 %
50 ms
10 s
0.5 %
Table 16: Relationship between Test Impulse Duration and SC/OC Interval
For actuators, a pulse-duty factor of 0.5 % between the SC/OC interval and the test impulse
duration has provided good results in practice. The value for the test impulse duration must
always be lower than the value for the SC/OC interval.
If line monitoring is not functioning properly, a short-circuit or an open-circuit is indicated.
Line monitoring does not affect the
Channel OK
,
Submodule OK
and
Module OK
statuses,
see Chapter 4.4.
