Introduction:
The ZT-2550 and ZT-2551 series modules are small-sized wireless ZigBee converters based on the IEEE802.15.4 standard that allow RS-232, RS-485 interface to be converted to a personal area ZigBee network. The typical transmission of ICP DAS ZT series ZigBee products is 700 meters (LOS, line of sight), with a transmission frequency range of between 2.405 GHz and 2.48 GHz, separated into 5 MHz sectors, providing 16 channels and 16384 PAN IDs. ZT-2000 series is not only a long distance wireless converter but also can act a ZigBee router to extend the transmission range and improve the quality of wireless signal.

ZT-2000 series products are specification for a suite of high level communication protocols using small, low-power digital radios module, which are fitted the ZigBee 2007 (ZigBee Pro) of ZigBee Alliance. In the ZigBee network, it is only allowed one ZigBee Host and called “ZigBee Coordinator”, ZT-2550 series products, are used to initialize and manager the routing. In addition, one ZigBee network is able to manager 255 ZigBee router and responsible for receiving or bypassing data from parent or child node.

For more information, please refer to the relevant web site and documents for these devices, which can be found at following link:
http://oldweb.icpdas.com/root/product/solutions/industrial_wireless_communication/wireless_solutions/wireless_selection.html#e
http://ftp.icpdas.com/pub/cd/usbcd/napdos/zigbee/zt_series/document