In automation technology, transmitters create an electric signal ranging from 0/4 mA … 20 mA that is proportional to a measured signal (i.e. temperature, pressure, differential pressure, fill level, flow volume).
Whether you want to connect 2-wire and 3-wire transmitters or active signals coming from externally supplied field devices and 4-wire transmitters, as part of our remote I/O solution “LB system”, we offer highly reliable analog modules with Ex ia inputs for use in Zone 2/22 or Class I, Div. 2 explosion hazardous areas. These modules not only power the connected transmitter, but also digitize the measured current for bus communication. Several of these transmitter power supplies can also be used for connection of 3-wire transmitters up to 23 mA. In these applications, the third wire is used for active return line current ranging from 4 mA … 20 mA or 0 mA … 20 mA.
The LB system remote I/O analog inputs are available in the following versions:
The modules support lead breakage detection, short circuit detection, and live-zero status. Galvanic isolation separates the inputs from bus and power. In addition, they are hot-swappable, which allows quick and easy module replacement without time-consuming system shutdowns.
Many of these transmitter power supplies also offer HART communication features, saving you the costs of additional measurement devices. For instance, the first variable of a flow transmitter can be transmitted as a
4 mA … 20 mA signal while the temperature of the medium is detectable via HART protocol.