4
57-651 Eclipse
®
SIL Certified Safety Manual for Enhanced Model 705-51AX-XXX
3. All products chosen for use in the SIF must meet the
requirements of IEC 61508 for the given SIL Capability
level or be justified based on proven in use data.
Eclipse Enhanced Model 705 meets the hardware architec-
tural constraints for up to SIL 2 at HFT = 0 (or SIL 3 at
HFT = 1) when the listed failure rates are used.
The architectural constraint type for the Eclipse Enhanced
Model 705 is B.
The exSILentia tool from exida is recommended for design
verification. This automatically checks all three limits and
displays the results for any given design. The Enhanced
ECLIPSE Model 705 is in the exSILentia database. This
tool contains all needed failure rate, failure mode, SIL
Capability and common cause data as well as suggested
proof test methods.
2.0
Level Measuring System
Figure 1 shows the structure of a typical measurement
system incorporating the Enhanced Magnetrol
®
Model 705 Guided Wave Radar transmitter.
This SIL 2/3 certified device is only available with an analog
signal (4–20 mA) with HART digital communications.
The measurement signal used by the logic unit must be the
generated analog 4–20 mA signal proportional to level.
For fault monitoring, the logic unit must recognize both a
high alarm (
≥
21.5 mA) and low alarm (
≤
3.6 mA).
NOTE: Care must be taken to ensure the loop continues to operate
properly under a high alarm condition if the logic unit or loop
contains intrinsic safety barriers.
The only unsafe mode is when the unit is reading an
incorrect level within the 4–20mA range: ±2% of span or
the measured error published in I/O Manual 57- 600,
whichever is greater. MAGNETROL defines a safe failure
as one in which the 4–20 mA current is driven out of range
(i.e., less than 3.8 mA or greater than 20.5 mA).
2.1
Applicable Models
This manual is only applicable to the following Enhanced
ECLIPSE Model 705 Guided Wave Transmitter:
705-51Ax-xxx (SIL 2, HFT 0)
NOTE: Please ensure that the Model 705 transmitter and probe are
installed as a set matched by the Serial Number shown on the
name plates.
Actuator
PACTware
™
with
Eclipse
®
3.x DTM
HART Modem
Eclipse
®
Model 705
Logic
Unit
Figure 1
Typical System
