Siemens SIMATIC ET 200S Installation And Operating Manual page 124

Fail-Safe Modules
7.5 4/8 F-DI VDC24V PROFIsafe Digital Electronic Module
Special Features of Fault Detection (Use Case 2.2)
The following table presents fault detection according to the sensor supply and the
parameter assignment for the short-circuit test:
Table 7-23
Short circuit in DI 0 with DI 1
Short circuit in DI 0 with DI 4
Short circuit in DI 0 with DI 5
P-short circuit in DI 0
M-short circuit in DI 0
Discrepancy error
P-short current in sensor supply 1
M-short circuit in sensor supply 1, or
sensor supply 2 defective
Short circuit in sensor supply 1 with
sensor supply 2
Fault in read/test circuit
Supply voltage fault
*: 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.
7-64
EM 4/8 F-DI DC24V PROFIsafe: Fault Detection (Application 2.2)
Example of fault Fault detection when ...
Internal Sensor Supply and
Deactivated Short-Circuit
Test
Yes*
No
Yes*
Yes*
Yes*
Yes
No
Yes
No
Yes
Yes
ET 200S Distributed I/O System - Fail-Safe Modules
Hardware Installation and Operating Manual, 07/2005, A5E00103686-04
External Sensor Supply
Yes*
No
Yes*
Yes*
Yes*
Yes
No
Yes
No
Yes
Yes