ADM239-AA – Two Process Input signal Auto Averager Unit

Our ADM239-AA is a Two Input Auto Averager Unit that is suitable for providing the average of two flow, temperature, pressure, or other process input signals in SIL 1, SIL 2, and SIL 3 rated (EN 61508-2) safety instrumented system (SIS) loop applications. If either of the input process signals is lost, shut off, or goes open circuit, the unit will automatically switch to a straight repeater of the remaining active input signal.

Input: Typical 4-20mA signals from field flow, temperature, pressure transmitters, etc.  Current may be specified up to 100mA max inputs (passive ports). Voltage may be specified up to 150Vdc max inputs. The inputs share a common internal 0V, however an isolated version is available on request if required.

Output; Any standard process current or voltage in the range of; Current source up to 22mA max, with drive voltage 24Vdc. Voltage source up to 20V max output.

Typical 4-20mA application/function; The output signal will represent the average of the two input signals, unless either one of the inputs is lost, shut off, or goes open circuit, @<3.8mA the unit will automatically switch to just repeat the remaining active input signal.