TRICONEX Invensys 3805E Module Use In Good Condition

Product:TRICONEX Invensys 3805E

Analog Output Module in good condition

The Analog Output (AO) module receives output signals from the Main Processors on each of three legs. Each set of data is voted, and a healthy leg is selected to drive the eight 4-20 mA outputs. The AO module monitors its own current outputs (as input voltages) and maintains an internal voltage reference that provides self-calibration and module health infornation. The output over-range capability of the module is +6 percent.

Each leg on t he AO module has a current loopback circuit, which verifies the accuracy and presence of analog signals independently of load presence or leg selection. A non-selected leg cannot drive an analog signal to the field. A LOAD indicator is set to ON if the module cannot drive current to one or more outputs because of an open loop.

The AO module provides for redundant loop power sources with individual indicators, PWR1 and PWR2, set to ON when loop power is present. External loop power supplies are provided for each application. Each module requires up to 1 ampere @ 24-42.5 volts.

Each module sustains complete, ongoing diagnostics for each leg. Failure of any diagnostic on any leg activates the FAULT indicator, which in turn activates the chassis alarm contact. The FAULT i ndicator po ints to a 1 eg fault, not a module failure. The in odule is guaranteed to operate properly in the presence of a single fault and may continue to operate properly with certain kinds of multiple faults.