So far in this blog I have touched on the Smart Grid and the BMS. In this post I would like to cover some areas of cellular technology that is available and used today.
In the field of industrial automation , remote monitoring and alarm systems are used to keep site administrators informed on things such as equipment health , usage levels eg. fuel , environment conditions and unauthorised intrusion. The remote data collection devices are typically connected to a management or control centre over RS - 485 or the Ethernet which also depends on factors such as the distance and the type of management systems. BACnet , ModBus and LonWorks are some of the management systems that are in use for monitoring and automation purposes. In many cases , the Ethernet connection can be replaced or augmented with cellular technology.
The use of cellular communications has some advantages like being wireless which means no stringing cables over long distances , ability to connect to your remote site from any locations and any number of locations , have options to connect to your remote sites by cell phone or PDA , the infrastructure is already provided by the cellular service provider which means savings in costs and hassle, and it is also easier and a cost effective way to monitor a greater number of sites and locations.
The cellular connections can be established in data communications by installing a cellular modem or a cellular module with modem functions if your control component at the remote site communicates over a serial interface. The disadvantages are low bandwidth and low speed transmission , potentially high recurring costs due to per - minute cellular charges and the cumbersome configuration and application development for modem communications.
However, the cellular IP modem which connects to the on-site PLC or embedded computer over a serial line is a far better option. Using an IP address the 2G cellular technology allows the monitoring centre to connect to the device over the Internet. It does not require a separate modem at the monitoring centre , the remote PLC or embedded computer can be treated as a network device or as a physically attached serial device and it has potentially lower recurring costs due to per-data-packet cellular charges.
A cellular connection can be established through a cellular router in remote monitoring equipment that relies on Ethernet for communications.
The cellular router when combined with an intelligent I/O module can be lightweight and a cost -effective alternative to using PLCs.
Cellular technology can be used for remote monitoring of power plants and other industrial plant whereby there are generators , UPS (Uninterrupted Power Supplies) etc. and we need to monitor the fuel levels, and basically remote monitoring of the building management systems.
- A GSM modem is installed on to the system and is linked to all essential equipment requiring monitoring.
- The servers constantly monitors your system and records all essential data and specified alarms.
- Any alarm generated is immediately elevated to an alert status and automatically transmit’s an alarm message via SMS to your mobile or via email.
- A service team could also be notified of the alarm and after analysing the data they will despatch an Engineer to correct any faults.
- This is available 24 hours a day and 7 days a week.
Cellular technology has a niche in remote monitoring and we can still be aware of system status by receiving the SMS from the service team and also by logging into the web portal of the remote monitoring systems.
http://www.moxa.com/newsletter/connection/2008/05/Cellular_Technology_for_Remote_Monitoring_and_Alarm_Systems.htm?utm_source=GlobalSpec&utm_medium=directory&utm_campaign=Technical+Article
http://www.csimn.com/CSI_pages/appsCellular.html
http://www.bacnet.org/Bibliography/DMF-7-96/DMF-7-96.htm
http://www.remoalert.co.uk/
