8
Electrical installation
Safe digital outputs (F-DO.)
Manual – MOVISAFE
®
CS..A Safety Card
56
Note the dependency of the achieved Performance Level (PL) and SIL on the selected
connection variant of the safe digital outputs. The switching state of both outputs F-
DO00 and F-DO01 must be stable at least once within 60 seconds for a minimum of 2
seconds. The error response "Output error" is triggered if this stable state cannot be
effected, thus resulting in a failure to execute the diagnostics in their entirety. The con-
sequence of this is that the respective digital output is switched to the safe state
"open".
Diagnostics can be activated optionally for the 24 V switch outputs F-DO00 and F-
DO01. The diagnostics recognizes an interrupted output current circuit if the value of
the output current falls below that of the "Minimum current for wire break monitoring"
with through-connected output.
If a wire break is detected, the "Output error" error response occurs, which blocks all
outputs.
8.6.2
Capacitive loads
•
A capacitive load of no more than 10 nF may be connected to the output without
any additional measures. Capacitive loads often occur in electronic assemblies as
buffer capacitors.
If the capacitive load has a diode in series to its input, the maximum load capacity
permitted is 12 µF. This diode is often installed as polarity protection diode in elec-
tronic assemblies.
•
If the capacitive load is not known or is higher than 10 nF, the inrush current must
be limited to the permitted values of the output pursuant to DIN EN 61131-2.
INFORMATION
Due to the thermal load of the output components, the maximum switching frequency
of the digital outputs in the presence of capacitive loads must be limited to the value
specified in chapter "Technical data" > "Safe digital outputs".
8.6.3
Inductive loads
Inductive loads are, for example, relays, contactors, valves.
•
Inductive loads always must be connected between sourcing and sinking outputs.
•
The energy stored in the load inductance, which depends on the inductance value
and the current, may not exceed the values specified in chapter "Technical data".
NOTICE
Operation of inductive loads without freewheeling diode may damage the
MOVISAFE
®
CS..A safety card.
Damage to the MOVISAFE
®
CS..A safety card
•
Inductive loads must always be connected via a freewheeling diode. The safe di-
gital outputs of the MOVISAFE
®
CS..A safety card are not equipped with a free-
wheeling diode.
•
Varistors and other overvoltage protection elements are not permitted.
24842532/EN – 04/2018
