Nordic ID RF601 User Manual

Nordic ID RF601 User Manual Manual pdf 13 page image

© 2006 Nordic ID OyRF601 User Manual May 2006 Version 17��2. System2.1 System overviewThe Nordic ID RF601 Wireless Data Collection System consists of three principal components:• Nordic ID RF601 Hand Terminal(s)• Nordic ID RF601 Base Station(s)• The application software that runs on the Host ComputerThis picture (figure 4) illustrates how a Nordic ID RF601 operates. The information will be sent from the handheld terminalvia the base station to the host application. In some configurations the base station includes an ethernet connector whichcan be used to connect the base station to the host computer via LAN network.2.2 Principles of OperationThe Nordic ID RF601 is a Hand Terminal which communicates wireless with PC application software via Nordic ID RF600Base Station(s). A Base Station can be connected directly to the Host Computer using an RS232C interface, or vianetwork by using the Ethernet connector (optional feature). The Hand Terminals can send/receive data to/from the HostComputer using the specific Communication protocol. Data transfer between the system components is always checksummed and acknowledged. This prevents any loss of data.2.3 Communication between the Base Station and the Host ComputerThe Base Station keeps listening the radio channel and the RS232C interface this is in order to check if the Hand Terminalsor the Host Computer have data to send. When the base Station receives data from the Hand Terminal, it verifies theintegrity of the data frame by using CRC check summing; only correct messages are then passed to the RS232C port.The CRC is not removed from the message so that it can be used to check the hardware link between the Base Stationand the Host Computer.When the Base Station receives a data from the Host Computer, the CRC checksum is recalculated for the data frame.Only if the message is correct will it be transmitted to the radio channel.Fig. Diagram of the communication