Settings; Safety-Related Characteristics - Siemens SITRANS P DS III Operating Instructions Manual

Functional safety

8.3 Settings

Operational reliability
According to IEC 61511-1, Section 11.4.4, the hardware fault tolerance (HFT) can be
reduced by one (values in brackets) for transmitters and final controlling elements with
complex components if the following conditions apply to the device:
● The device is proven in operation.
● The user can configure only the process-related parameters, e.g. control range, signal
direction in case of a fault, limiting values, etc.
● The configuration level of the firmware is blocked against unauthorized operation.
● The function requires SIL of less than 4.
See also
General functional safety (http://www.siemens.com/safety)
Functional safety in process instrumentation (http://www.siemens.com/SIL)
8.3 Settings
Introduction
When using the device for functional safety, follow these steps:
Procedure
1. Setting safety-relevant parameters (Page 144)
2. Checking the safety function (Page 134)
3. Enabling write protection (Page 150)
8.4

Safety-related characteristics

The safety characteristics necessary for using the system are listed in the "SIL Declaration of
Conformity". These values apply under the following conditions:
● SITRANS P DS III pressure transmitters are only used in applications with a low demand
rate for the safety function (low demand mode).
● The safety-relevant parameters/settings were entered before the safety-instrumented
operation via PROFIBUS communication. Check the safety-relevant parameters/settings
by means of PDM; refer to chapter "PROFIsafe Configuration (Page 144)".
● The safety function test has been concluded successfully.
● The pressure transmitters are protected from accidental and unauthorized
changes/operation.
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SITRANS P DS III/P410 with PROFIBUS PA
Operating Instructions, 02/2016, A5E00053276-08