Siemens SIMATIC ET 200S - Page 137

Fail-Safe Modules
7.6 EM 4 F-DI/3 F-DO DC24V PROFIsafe digital electronic module
ET 200S Distributed I/O System - Fail-Safe Modules
Installation and Operating Manual, 08/2008, A5E00103686-07
137
Supported Power Modules
Table 7- 26 EM 4F-DI/3F-DO DC24V PROFIsafe: Power module for SIL/Category/PL
Power Module achievable SIL/Category/PL
Supply through PM-E DC24V, PM-E
DC24..48V/AC24..230V or PM-E
DC24..48V
with 1oo2 sensor evaluation of the SIL2/Category 3/PLd
sensor
Switching Grounded Loads
If the EM 4 F-DI/3 F-DO DC24V PROFIsafe switches loads that have a chassis-ground
connection (for example to improve EMC characteristics) and if chassis and ground are
connected at the power supply being used, a "short-circuit" is detected.
From the perspective of the F-module, the M-switch is bridged by the chassis-ground
connection (refer to the diagram below as an example of an EM 4 F-DI/3 F-DO DC24V
PROFIsafe).
Remedy:
● Using the PM-E F pp DC24V PROFIsafe
● The value of the resistance between chassis and ground at the load end must be greater
than 100 kΩ
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Figure 7-32 Switching Grounded Loads (resistance exists between chassis and ground)
Capacitive Crosstalk of Digital Input/Output Signals
refer to "Properties of the power module PM-E F pm DC24V PROFIsafe" .