5
Pressure Transmitter Series 2000T and 265Ax, 265Gx, 265Vx, 265Dx, 265Jx, 267Cx, 269Cx
SM 265/7/9 SIL-EN
Instructions for Functional Safety
IMPORTANT
This documentation applies to the transmitter 265xx as a part of a safety function.
The following table shows the reachable Safety Integrity Level (SIL) of the entire safety-related system for systems
of type B, depending on the safe failure fraction (SFF) and the hardware fault tolerance (HFT). Systems of type B
are e.g. sensors with complex components like microprocessors (see also IEC61508, Part 2).
1)
Acc. to IEC 61511-1, Part 11.4.3, the hardware fault tolerance (HFT) of sensors and final control elements with complex com-
ponents can be decreased by one (value in brackets), if the following requirements are met:
– The device is proven-in-field.
– The user can only configure process-related parameters like the measuring range, signal direction in case of fault, etc.
– The device configuration level is access-protected, e.g. by jumper or password
(here: code number or key combination).
– The function has a required Safety Integrity Level (SIL) less than 4.
The transmitter meets all requirements.
Fig. 6-2: Safety function (e.g. for pressure limit monitoring) with 265DS as a subsystem
1)
265DS with local operation option and adjustable lower and upper range value and damping
2)
Computer with user interface like SMART VISION for setting all parameters
e.g. alarm behavior, max. alarm, operating mode, etc.
3)
Hand-held terminal for setting all parameters, e.g. alarm behavior, max. alarm,
operating mode, etc.
The transmitter 2000T / 2600T produces an analog signal (4...20 mA) proportional with the differential pressure or
gauge pressure / absolute pressure. This analog signal is fed to a subsequent logic unit, e.g. a PLC or limit trans-
mitter, and monitored for violation of a defined maximum value. The logic unit must be capable of recognizing HI
alarms (adjustable between 21 and 22.5 mA) and LO alarms (3.6 mA) in order to allow for malfunction detection.
Safe Failure Fraction (SFF)
Hardware Fault Tolerance (HFT)
0
1 (0)
1)
2 (1)
1)
< 60 %
impermissible
SIL 1
SIL 2
60...< 90 %
SIL 1
SIL 2
SIL 3
90...< 99 %
SIL 2
SIL 3
–
≥
99 %
SIL 3
–
–
1)
3
)
2)
PC with graphical
user interface
e.g. DSV401 (SMART VISION)
FSK
modem
Hand-held
terminal
Transmitter 265DS
Logic unit
e.g. PLC
Limit transmitter
etc.
4...20 mA
Actuator
