Farming has become more efficient with high-tech machinery and communication systems. M2M (machine-to-machine) technology has helped farmers to increase their production with monitoring and control systems. Farmers can review the status of their crops and weather conditions through a PC or cell phone and can take immediate action remotely. They can remotely do things like turn an irrigation system on or off, monitor moisture levels, and monitor temperature.
Zigbee Wireless Technology can be used to implement a wireless machine to machine agriculture application. Zigbee wireless technology operates in the 2.4 GHz frequency and supports mesh, star and cluster tree topologies. Each zigbee network has an RF channel, a PAN ID, and each node has a unique node ID. The network configuration is done through a software utility. Zigbee networks support transparent, broadcast or Modbus communication modes. Zigbee networks require one host or master like ZB-2550-T to be a network coordinator which initializes and determine the most optimal transmission path between nodes. ZB-2550-T can bring RS-485 or RS-232 devices to Zigbee wireless communication. Zigbee networks may have many slave converters like ZB-2551-T for transmitting and receiving with end devices. Wireless remote input output devices like ZB-2060-T or ZB-2017C-T can be used for turning irrigation systems on or off or taking temperature measurements. SCADA software like KingView can be used to interface with the wireless Zigbee hardware through Modbus drivers. RS-485 based GPS devices like GPS-721 can also be used with Zigbee wireless networks for tracking farming vehicles. The typical communication distance for Zigbee hardware like ZB-2550-T and ZB-2551-T is 100 meters and the standard antenna is omni-directional. Longer range versions can communicate up to 700 meters. Directional antennas like ANT-15YG or omnidirectional antennas like ANT-15 may extend communication distances up to 9 Km.
Wireless Cellular Technology can be used to implement a wireless machine to machine agriculture application. GSM is the Global System for Mobile Communication. GPRS is the General packet Radio Service. GSM and GPRS operate over 2G quad band 850/900/1800/1900 Mhz. M2M programmable controllers like G-4500 come in different options like 2G and 3G options for different coverage in different areas. Some remote applications require 3G coverage and speed and others can operate optimally with quad band coverage. GT-540P is a wireless intelligent GPRS remote terminal unit with GPS and a 2 GB micro SD card for remote monitoring applications. It has 6 digital inputs, 2 digital outputs and 1 analog input. G-4500 and GT-540P support Modbus RTU communication and are ideal for vehicle tracking in farming applications. ICP DAS USA provides M2M RTU center which allows for easy interface with remote Modbus RTU devices. The Modbus RTU devices can easily be accessed through SCADA software like KingView.