HB-37350-810-01-50F-EN PSC1-C-10 Installation manual V2.1.docx Page 170 of 189
Version: 50F
12.3.5 Hardware specification
In the hardware specification, the complete system layout and in particular the components
used here are to be described with their specific characteristic data. The hardware
specification is used as the basis for determining the safety level achieved based on the
architecture and the characteristic data of all devices involved in a safety function.
In addition, the design measures for protection against systematic and common cause failures
are to be stated in the hardware specification.
12.3.5.1 Selection of SRP/CS and equipment
The SRP/CS (safety related parts of control system) are to be selected appropriately for
achieving the safety level required for each safety function. The components are to be marked
with the safety-related function in a complete overview of the system and assigned to the
individual safety functions. The safety-related characteristic data are to be determined for
these components.
The characteristic data include the following values:
MTTF
d
= mean time to dangerous failure
DC
avg
= average diagnostic coverage
CCF = common cause failure
On a SRP/CS, the software and systematic failures are also to be considered.
In principle, an analysis is to be undertaken on the SRP/CS involved in a safety function
according to the scheme sensor / PES / actuator.
To Next Page
Loading...
Need help?
General
