TRICONEX 3805E nalog Output Modules 3806E

An analog output (AO) module receives output signals from the main processor module on each of three channels. Each set of data is then voted and a healthy channel is selected to drive the eight outputs. The module monitors its own current outputs (as input voltages) and maintains an internal voltage reference to provide self-calibration and module health information.
Each channel on the module has a current loopback circuit which verifies the accuracy and presence of analog signals independently of load presence or channel selection. The module’s design prevents a non-selected channel from driving an analog signal to the field. In addition, ongoing diagnostics are performed on each channel and circuit of the module. Failure of any diagnostic deactivates the faulty
channel and activates the Fault indicator, which in turn activates the chassis alarm. The module Fault indicator merely indicates a channel fault, not a module failure. The module continues to operate properly with as many as two channels failed. Open loop detection is provided by a LOAD indicator which activates if the module is unable to drive current to one or more outputs.