JUMO 14597 safetyM STB/STW Ex - Safety Temperature Limiter and Safety Temperature Monitor Operating Manual - Manual (Page 51)

6 Safety Manual
45 2013-04-01
6.9.2 Safety-relevant system features
Device versions differ in the following architectures:
The evaluation unit of the JUMO safetyM STB/STW Ex in the STW and STB versions is implemented as 1oo2D architecture.
Figure 2: The types with a single sensor are executed in one-channel sensor systems (1oo1)
Figure 3: The variants with two sensors are consistently structured with two channels.
Systems have a lifetime of ten years.
The proof check for SIL2 and SIL3 certified systems is also ten years.
If the temperature is above/below the admissible limits, the system switches to the safe state without delay. Premature switch-
ing is admissible if a malfunction is detected.
The following are monitored:
- Probe break
- Probe short circuit
- Random hardware failure in one channel
The following are monitored:
- Probe break in sensor system subsystem
- Probe short-circuit in sensor system subsystem
- Reverse voltage polarity of the probes
- Random hardware failure in one channel