Siemens SIMATIC Operating Instructions Manual page 128

Fail-Safe Electronic Modules
8.3 F -Switch PROFIsafe Digital Electronic Module
Specific Characteristics for Fault Detection (Use Cases 3.1 and 3.2)
The following table presents fault detection according to the sensor supply and the
parameter assignment for the short-circuit test:
Table 8-28
Short circuit of DI 0 with DI 1
Short circuit of DI 0 with DI 2
Short circuit of DI 0 with DI 3
P-short circuit of DI 0
M-short circuit of DI 0
Discrepancy error
P-short circuit of Vs1
M-short circuit of Vs1, or Vs2 defective
Short circuit of Vs1 with Vs2
Fault in read/test circuit
Supply voltage fault
*: Fault is detected only in case of signal corruption. That is, the signal read differs from the sensor
signal (discrepancy error). If there is no signal corruption relative to the sensor signal, fault detection
is not possible and is not required from a safety standpoint.
Requirements for Machine Protection Applications With Category 4
The following requirements apply to machine protection applications with Category 4:
● State-of-the-art wiring must be used between the sensors and the automation system or
● All short circuits listed in the above table are detected. Detection of a short circuit is
Processes for detection of all short circuits are also permissible if individual short circuits are
not detected, provided:
● The short circuits do not cause corruption of read signals compared to the sensor signals
● The short circuits cause corruption of read signals compared to the sensor signals, but in
128
F-Switch PROFIsafe Electronic Module: Fault Detection (Use Cases 3.1 and 3.2)
Example of Fault
between the automation system and the actuators to prevent short circuits.
sufficient in this case, because two faults must exist for the short circuit to occur (both of
the short-circuited signal cables exhibit an insulation fault). Thus, a multiple short-circuit
analysis is not required.
or
the direction that ensures safety.
Fault detection with internal sensor supply and enabled
short-circuit test for ...
Sensor 2-channel equivalent
Yes*
Yes*
Yes*
Yes
Yes*
Yes
Yes
Yes
Yes
Yes
Yes
ET 200pro Distributed I/O System - Fail-Safe Modules
Operating Instructions, 05/2007, A5E00394073-02
Sensor 2-channel
nonequivalent
Yes*
Yes
Yes*
Yes
Yes*
Yes
Yes
Yes
Yes
Yes
Yes