iSMA-B-W0202 Modbus User Manual
version 1.2
Page 9 / 49
Grounding and shielding
In most cases, IO modules will be installed in an enclosure along with other devices which
generate electromagnetic radiation. Relays, contactors, transformers, motor invertors etc. are the
examples of these devices. This electromagnetic radiation can induce electrical noise into both
power and signal lines, as well as direct radiation into the module causing negative effects on the
system. Appropriate grounding, shielding and other protective steps should be taken at the
installation stage to prevent these effects. These protective steps include control cabinet
grounding, cable shield grounding, protective elements for electromagnetic switching devices,
correct wiring as well as consideration of cable types and their cross sections.
RS485 Network Termination
The transmission line effects often present problem on data communication networks. These
problems include reflections and signal attenuation.
To eliminate the presence of reflections from the end of the cable, the cable must be terminated
at both ends with a resistor across the line equal to its characteristic impedance. The both ends
must be terminated since the direction of propagation is bidirectional. In the case of an RS485
twisted pair cable. This termination is typically for 120 Ω.
Module configuration
W0202 can be configured by RS485 Modbus registers or directly by USB connection and iSMA-
Configurator software. The iSMA-Configurator can be downloaded from www.support.gc5.pl.
When the module is connected, it appears in the hierarchy tree window (left part of the screen).
The next step is to read module configuration using the “Read Module” button or to read
configuration from a file using the “Load From File” button.
If you want to save changes in the module, you need to use the “Write Module” button. This
command writes all parameters down to the module.
WARNING! Radio settings only takes effect after the module restarting.