Siemens SIMATIC ET 200eco Manual page 76

Digital F I/O Module
Assignable Parameters for Application 3.2
Set the parameter "evaluation of sensors" to "1oo2 evaluation" and the parameter
"type of sensor interconnection" to "2-channel non-equivalent" for the relevant
input. Deactivate the parameter "short-circuit test."
Special Features of Fault Detection (Application 3.1 and 3.2)
The following table presents error detection according to the sensor supply and the
parameter assignment for the short-circuit test:
Table 8-8
Example of Error
Short circuit in DI 0 with DI 1
Short circuit in DI 0 with DI 4
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 1 defective
Short circuit in sensor supply 1 with
sensor supply 2
Error in read/test circuit
Supply voltage fault
* Error 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,
error detection is not possible and is not required from a safety standpoint.
Requirements for Machine Protection Applications with Category 4
The requirements for machine protection applications with Category 4 are:
•
Wiring between sensors and the automation system and between the
automation system and the actuators must be state-of-the-art and must comply
with standards for preventing short circuits.
•
All short circuits detected in the table above are detected. In this case, it is
sufficient to detect one short circuit, because it required two faults to be
generated (both of the short-circuited signal cables indicate an isolation fault).
Consequently, a multiple short-circuit analysis is not required.
Methods for detecting all short circuits are permissible even if no individual short
circuits are detected, provided they do one of the following:
•
Do not cause corruption of read signals compared to sensor signals
•
Cause corruption of read signals compared to sensor signals, but in the
direction that ensures safety
8-24
ET 200eco 4/8 F-DI: Fault Detection (Applications 3.1 and 3.2)
Fault detection with internal sensor power supply
and activated short-circuit test for...
Sensor 2-channel
equivalent
No
Yes *
Yes
Yes *
Yes
Yes
Yes
Yes
Yes
Yes
ET 200eco Distributed I/O Station Fail-Safe I/O Module
Sensor 2-channel non-
equivalent
No
Yes
Yes
Yes *
Yes
Yes
Yes
Yes
Yes
Yes
A5E00297494-02