60 User GuideConfiguring the LWT300 with a computerLWT300 instruments can also be configured with a computer. All configuration options explainedpreviously can be performed via a software communication tool and a HART driver (see also “ConfiguringHART communication” on page 71). The following provides an overview of the configuration setup.NOTICEFor instrument configuration with software tools running on a PC, you must disconnectthe LWT from the flow computer/RTU—Figure 43 LWT instrument Modbus connection to a PC or laptop via USB/RS485 converterDescription1 Software toolDriver and device management tool for configuration and parameterization of intelligent field devices.2 USB/RS 485 converter (not provided by ABB)At end of Modbus interface, with 120 Ω resistance between ‘(A) Tx/Rx+’/‘(B) Tx/Rx−’3 RS 485 cable (not provided by ABB)Half-duplex wiring with (A) Tx/Rx+, (B) Tx/Rx− and GND• Connect ‘Tx+’ and “Rx+’• Connect ‘TX−’ and ‘Rx−’LWT guided wave radar level transmitters can be configured with the aid of various softwarecommunication tools such as ABB Field Information Manager, a software configurator that can bedownloaded at www.abb.com/measurement.With the graphical user interface all configuration possibilities are available. The procedure for programinstallation is described in the appropriate installation manual delivered with the software.The transmitter can be configured, read out and tested via the program. Each configuration step is