Siemens SIWAREX MS, Device Manual

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Hardware
Configuration and Assembly
4.1 Configuring the Hardware
SIWAREX MS is an analog expansion module running in the SIMATIC S7-200
automation system.
The maximum possible number of SIWAREX MS expansion modules per rack
corresponds with the maximum number of expansion modules of the respective
CPU type according to the S7-200 system manual.
CPU type Max number of
SIWAREX MS
CPU 222 2
CPU 224 7
CPU 226 7
Table 4-1 Expansion module in the S7-200 system
The utilization of other expansion modules can reduce the permitted number of
SIWAREX MS. Check the current requirements on the expansion bus according to
the S7-200 system manual.
Selecting the suitable SIMATIC CPU, the SIMATIC HMI (Human Machine
Interface) does not only depend on weighing technology requirements but also on
the overall job that the automation system has to perform.
4.2 Structure to EMC Guidelines
SIWAREX MS is a highly precise measuring device, which must measure low
signal levels (approx. 1.5
µ
V) reliably. Because of this, proper assembly and wiring
are absolutely essential for fault-free operation.
4.2.1 Definition: EMC
EMC (Electromagnetic Compatibility) describes the ability of an electrical device to
function without faults in a defined electromagnetic environment without being
influenced by its surroundings and without negatively influencing the surroundings.
4.2.2 Introduction
Although SIWAREX MS was developed for use in industrial environments and
meets high EMC specifications, you should carry out EMC planning before
installing your controller to determine and take into account any possible
interference sources.
4.2.3 Possible Effects of Interference
Electromagnetic interference can influence the automation system and the
SIWAREX MS in various ways:
- Electromagnetic fields that have a direct influence on the system
- Interference through process cabling (e.g. measurement lines)
SIWAREX MS 4-9