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"
).