Farming has become more efficient with high-tech machinery and advanced communication systems. M2M (machine-to-machine) technology has helped farmers increase their production through improved 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 turn irrigation systems on or off, monitor moisture levels, and monitor temperature.
ZigBee wireless technology can be used to implement wireless machine-to-machine agriculture applications. ZigBee operates in the 2.4 GHz frequency band 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. Network configuration is done through a software utility. ZigBee networks support transparent, broadcast, or Modbus communication modes.
ZigBee networks require one host or master, such as ZB-2550-T, to act as the network coordinator. It initializes and determines the most optimal transmission path between nodes. The ZB-2550-T can bring RS-485 or RS-232 devices into ZigBee wireless communication. ZigBee networks may include many slave converters like ZB-2551-T for transmitting and receiving with end devices.
Wireless remote input/output devices such as ZB-2060-T or ZB-2017C-T can be used for turning irrigation systems on or off or for taking temperature measurements. SCADA software like KingView can interface with ZigBee hardware through Modbus drivers.
RS-485-based GPS devices such as GPS-721 can also be used with ZigBee wireless networks for tracking farming vehicles.
The typical communication distance for ZigBee hardware like the ZB-2550-T and ZB-2551-T is 100 meters with a standard omni-directional antenna. Longer-range versions can communicate up to 700 meters. Directional antennas like ANT-15YG or omni-directional antennas like ANT-15 may extend communication distances up to 9 km.
Wireless cellular technology can also be used to implement machine-to-machine agriculture applications. GSM (Global System for Mobile Communication) and GPRS (General Packet Radio Service) operate over 2G quad-band 850/900/1800/1900 MHz.
M2M programmable controllers such as G-4500 come in multiple options including 2G and 3G, depending on coverage needs. Some remote applications require 3G speed and range, while others operate optimally with quad-band 2G 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 includes 6 digital inputs, 2 digital outputs, and 1 analog input. Both the 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 easy interface with remote Modbus RTU devices. These devices can easily be accessed through SCADA software like KingView.
