Connecting Mass 2100/Fc300; Setting The Eol Termination Dip Switches - Siemens SITRANS MASS 2100 Compact Operating Instructions

Connecting

4.2 Connecting MASS 2100/FC300

Note
Improvement of interference immunity
● Lay signal cables separate from cables with voltages > 60 V.
● Use cables with twisted wires.
● Keep device and cables at a distance from strong electromagnetic fields.
● Take account of the conditions for communication specified in the Technical data
(Page 47).
● Use shielded cables to guarantee the full specification according to HART/PA/FF/Modbus/
EIA-485/Profibus DP.
4.2 Connecting MASS 2100/FC300
4.2.1

Setting the EOL termination DIP switches

It is important to terminate the Modbus RS-485 line correctly at the start and end of the bus
segment. Impedance mismatch results in reflections on the line which can cause faulty
communication transmission.
If the device is at the end of the bus segment, it is recommended to terminate the device. The
following table shows the relation between the DIP switch settings and the permissible
communication interface set-ups.
Note
End Of Line (EOL) termination
The FCT010 EOL termination DIP switch is default set to EOL non-active. If the installation
requires active termination resistors, the DIP switches should be set to the EOL Active state.
Hazardous areas
Only change the DIP switches in hazardous areas when the device is deenergized.
30
CAUTION
SITRANS MASS 2100 & FC300 (FCT010)
Compact Operating Instructions, 05/2020, A5E40504094-AB