Analog modules
9.3 SM 336; F-AI 6 x 0/4 ... 20 mA HART
Fail-safe signal modules
Installation and Operating Manual, 01/2010, A5E00085586-10
237
Wiring scheme G: 4-wire transducer, internal sensor supply with module redundancy
Particularity:
● Short circuit between sensor supply voltage Vsn and Mn+ is handled.
● It is possible to detect an undervoltage at the transducer by reading back the sensor
supply in the module.
● It is necessary to incorporate the external elements into the application-specific safety
examination. This means appropriate external elements (e.g., Zener diodes) are needed
to achieve the respective Safety Integrity Level.
Note
1L+ and 2L+ can be fed from one power supply.
/
0
60
$,[P$+$57
60
$,[P$+$57
/
0
9V
0
0
9V
0
0
9V
0
0
9V
0
0
9V
0
0
9V
0
0
/
0
9V
0
0
9V
0
0
9V
0
0
9V
0
0
9V
0
0
9V
0
0
3
/
0
&+
&+
&+
&+
&+
&+
&+
&+
&+
&+
&+
&+
ZLUH
WUDQVGX
FHU
Figure 9-28 4-wire transducer, internal sensor supply with module redundancy
For information about the Zener diodes, refer to chapter "Calculation of the residual supply
voltage at the transducer (Page 239)".
To Next Page
Loading...
