Fail-Safe Modules
7.5 4/8 F-DI DC24V PROFIsafe Digital Electronic Module
ET 200S Distributed I/O System - Fail-Safe Modules
Installation and Operating Manual, 08/2008, A5E00103686-07
109
Parameter
Range
Default
Type of
Parameter
Effective
Range
Input delay
0.5 ms, 3 ms, 15 ms
3 ms
Static
Module
Short-circuit test
Cyclic/disable
Cyclic
Static
Module
Behavior after channel
faults*
Passivate the entire
module/Passivate the
channel
Passivate the
entire module
Static
Module
Channel n, n+4
Activated/deactivated
Activated
Static
Channel
group
Sensor supply
internal/external
internal
Static
Channel
group
Sensor evaluation
1oo2 evaluation /
1oo1 evaluation
1oo2
evaluation
Static
Channel
group
Type of sensor
interconnection
1-channel;
2-channel equivalent;
2-channel, non-
equivalent
2-channel
equivalent
Static
Channel
group
Behavior of discrepancy
Provide last valid value;
provide 0 value
Provide last
valid value
Static
Channel
group
Discrepancy time
10 to 30,000 ms
10 ms
Static
Channel
group
Reintegration after
discrepancy error
Zero signal test not
required/zero signal
test required
Zero signal
test not
required
Static
Channel
group
* This setting is only relevant when optional package
S7 Distributed Safety
V5.4 or higher is installed.
Input Delay of 3 ms Parameter
Note
When operating with 3 ms input delay, you must always use shielded cables if there is a
danger of overvoltage on the signal lines (see section "Electromagnetic Compatibility") to
prevent possible passivation of the fail-safe digital inputs and shutdown of the sensor power
supply.
If unshielded signal lines are used the safe behavior of the process variables is ensured.
Short-Circuit Test Parameter
This parameter can be used to activate short-circuit detection for channels set up for
"internal sensor supply."
The short-circuit test parameter is used to activate or deactivate the cyclic short-circuit test.
The short-circuit test is only useful for simple switches that do not have their own power
supply. Always use the internal sensor power supplies if the short-circuit test has been
activated (see also
"Applications for the 4/8 F-DI DC24V PROFIsafe electronic module").