Emc-Compliant Design; Definition: Emc; Introduction; Potential Interference - Siemens Siwarex U Device Manual

For estimating the maximum number of SIWAREX U that can be used in a system,
the following information is helpful:
Total width
n x 40 mm
Table 4-1 Requirements for n SIWAREX U
The maximal number of SIWAREX modules depends on the SIMATIC CPU or the
module ET200M, see SIMATIC catalogue.
The selection of the suitable SIMATIC CPU, the SIMATIC HMI (Human Machine
Interface), and the communication modules is not exclusively determined by the
requirements of SIWAREX U, rather by the overall job to be performed for the
automation system.

4.2 EMC-compliant design

SIWAREX U is a highly accurate measuring device, which has to reliably measure
the smallest of signals (approx. 1 μV). For this reason, professional installation and
wiring is absolutely necessary for fault-free operation.
4.2.1

Definition: EMC

EMC (electromagnetic compatibility) describes the ability of an electrical device to
function fault-free in a specific electromagnetic environment without either being
influenced by the environment or unduly influencing the environment.
4.2.2

Introduction

Although SIWAREX U was developed for use in an industrial environment and
meets high EMC requirements, you should carry out EMC planning and detect
potential sources of interference and include them in your considerations prior to
the installation of your control system.
4.2.3

Potential interference

Electromagnetic interference can affect the automation system and SIWAREX U in
various ways:
- Electromagnetic fields which affect the system directly
- Interference channeled in via bus signals (PROFIBUS-DP etc.)
SIWAREX U
3BHARDWARE CONFIGURATION AND INSTALLATION
Power requirements (5V)
from the SIMATIC
backplane bus
n x 100 mA
Main memory requirements
in the SIMATIC CPU
4100 bytes + n x 170 bytes
4-11