Project Introduction Storms and heavy rain can inflict significant damage to homes and property, especially in certain countries. In Thailand, the
government wished to establish a national rainfall monitoring system that could alert its citizens in time to prepare for a coming
storm. With advanced technology, the weather department would use the data to improve its ability to predict storm movement and
make the appropriate public announcements.
System Requirements Since a large number of rain gauges needed to be spread out all over the nation, the communication infrastructure was a critical issue. Instead of laying down cables, the government decided to use GPRS as the communication medium due to its excellent coverage throughout the country. Each monitoring station required a local storage system in case there was a communications failure. The I/O server that collected data from the rain gauge needed to be reliable and able to exchange data with the main controller. The following items were required for each monitoring station:
Event-driven transmission of counter values
Battery status monitoring
Backup data storage in the event of a communications failure
Data exchange over GPRS networks
System Description
For each monitoring station, the ioLogik E2210 I/O server was used to receive data from the rain gauge, the UC-7112 embedded computer was used for local data storage, and the OnCell G2150I GPRS/GSM modem was used to send data to the central management system. With the ioLogik E2210, automatic messages can be sent to a network host when an attached sensor changes status. Compared to traditional sensor polling methods, this proactive approach is easier to implement and provides more efficient communication between the host and I/O server. The UC-7112 no longer has to use precious CPU resources on polling the I/O server, since the ioLogik actively reports changes in sensor status. For local data storage, the UC-7112's onboard memory can be expanded using its SD slot. Finally, the OnCell G2150I provides each station with a reliable connection to the Internet over GPRS networks, and also allows the use of SMS for short message alarms.
Project Implementation
Why Moxa?
Conclusion
ioLogik E2210
Active Ethernet I/O server with 12
digital inputs, 8 digital outputs
UC-7112
RISC-based embedded computer
with 2 serial ports, dual LANs, SD
slot
OnCell G2150I
Quad-band industrial GSM/GPRS
modem with optical isolation
Proactive messages for changes in I/O status
MXIO library that reduces development effort for UC
platform
SMS tunnel mode for short message alarms and remote
control
For many applications, it is preferable to find a provider that can offer a complete solution in order to reduce integration effort. Moxa is one of the leading companies providing complete, industrial-grade solutions.
