The AV30 is a stand alone device that performs all the
functions of a gas controller and is classified as Type
B smart device according to IEC61508. It provides an
isolated 4-wire 4-20 mA output that is representative of
the received input 4-20 mA level. The AV30 contains
extensive self-diagnostics and will pass through the
detector current output to a specified failure state.
Pass-through means AV30 does not change the analog
output, it only sets the relays based on the analog value
provided by the sensor connected to its input.