iSMA-B-W0202 Modbus User Manual
version 1.2
Page 4 / 49
Introduction
iSMA-B-W0202 has been built to allow the extension of RS485 bus by using wireless technology
wherever use of network cable is impossible or unprofitable. Using two iSMA–B–W0202
modules allow to build the wireless 'bridge' for the RS485 by building wireless remote island
(one or more) for devices which communicate via Modbus RTU/ASCII - e.g. iSMA–B–MIX18
or iSMA–B–MIX38.
iSMA-B-W0202 (in addition to the RS485 port and wireless port) is equipped with 2SI (Special
Inputs) and 2DO (Digital Outputs max. 230 VAC/30 VDC 3 A ). It allows to use the device as an
I/O module or light controller communicating on Modbus RTU/ASCII. Algorithm implemented
in the processor allows the user to choose one of the three different modes:
Modbus Bridge
Modbus Bridge and I/O module (Digital Outputs work independent to the Special Inputs states)
Modbus Bridge and light controller (Digital Output states depends on assigned Special Inputs
states ). There are different Operating Modes available (see Special Application modes)
iSMA-B-W0202 is also equipped with a micro USB port which allows to configure the device
without the use of an external power supply (the device is powered through the USB port). This
solution gives the user an easy way, using 2 laptops, carry out the tests within the existing facility.
Revision history
Rev
Date
Description
1.0
2015.04.28
First edition
1.1
2016.12.29
The reason for the creation of new version of the document:
New functions:
•
New HVAC functions Heating and Cooling based on output thermostatic control with a setpoint
and differential value setting;
•
Added new input mode Time Relay NC [ms], Time Relay NO and NC in seconds, Input
Forwarding;
•
Added new input mode: Ordinary IO, Monostable Relay, Bistable Relay, Time Relay NO and NC
[ms], Time Relay NO and NC in seconds, Input Forwarding, Heating, Cooling with corresponding
Modbus registers;
•
Added reset output to default after input mode change
Improvements:
•
Added power Led flashing after IO watchdog triggered;
•
Changed IO watchdog reset after read/write registers through USB;
•
Added immediately detecting sensors short circuit and disconnection regardless of filter settings
on universal inputs;
1.2
2018.12.17
•
Added watchdog functionality for the Radio, if the radio does not receive the correct packet for
180 seconds, the radio module will restart.
Table 1 Revision history