Siemens SIMATIC ET 200AL System Manual page 2152

Electromagnetic compatibility
The entire architecture of HS modules is designed for fast processing of the signals. An
interference-free design is therefore critical when using HS modules.
The following rules apply to the wiring of HS modules with sensors and actuators:
● Keep the cables as short as possible
● Use shielded and twisted pair cables
● Low-impedance connection of the cable shield at the respective shield supports
● Short cable loop between shield support and terminal connection
Note
Interference-free design
Make sure that you pay close attention to the notes listed in the function manual Configuring
interference-free controllers (http://support.automation.siemens.com/WW/view/en/59193566)
when using HS modules.
Analog value processing
Function Manual, 06/2014, A5E03461439-AC
High-speed analog modules
8.2 ST modules vs HS modules
121