Fail-Safe Modules
7.6 EM 4 F-DI/3 F-DO DC24V PROFIsafe digital electronic module
ET 200S Distributed I/O System - Fail-Safe Modules
Installation and Operating Manual, 08/2008, A5E00103686-07
151
Special Features of Fault Detection in Application 1.2
The following table presents fault detection according to the sensor supply and the
parameter assignment for the short-circuit test:
Table 7- 30 EM 4 F-DI/3 F-DO DC24V PROFIsafe: Fault detection
Error detection condition ...
Example of fault
Internal sensor supply
and short-circuit test
are activated
Internal sensor supply
and short-circuit test
are deactivated
external sensor
supply
Short-circuit DI0 with DI1
Yes*
Yes*
Yes*
Short-circuit DI0 with DI4
No
No
No
Short-circuit DI0 with DI5
Yes*
Yes*
Yes*
P short-circuit DI0
Yes*
Yes*
Yes*
M short-circuit DI0
Yes*
Yes*
Yes*
Discrepancy error
Yes
Yes
Yes
P-short circuit in sensor
supply
Yes
No
No
M-short circuit in sensor
supply or defective
Yes
Yes
Yes
Short-circuit SS with DI0
Yes*
Yes*
Yes*
Supply voltage fault
Yes
Yes
Yes
*: Fault is detected only in case of signal corruption. In other words, the signal read differs from the
sensor signal (discrepancy error). If there is no signal corruption with respect to the sensor signal,
fault detection is not possible and is not required from a safety standpoint.
WARNING
If the short-circuit test is not activated or the sensor supply to digital inputs is set to
"external", the wiring between the sensor and the input channel must be short circuit-proof.
