The E+H RIA15 Process Indicator is available with 4 to 20 mA or with HART® protocol. In the HART® version up to 4 measured values of one sensor can be indicated in alternation. For this the indicator can be set as primary or secondary HART® master and actively inquire the values from the sensor. The small voltage drop of < 1V (< 1.9 V with HART®) is a huge advantage especially in Ex-applications, where in most cases only a reduced voltage is available.