The Analog Input (AI) function block accesses a single analog measurement value and status from an I/O channel. You can configure the channel type for each I/O channel to be the transmitter's 4 to 20 mA signal or the digitally communicated primary or non-Primary Variable from a HART transmitter.
The AI function block supports block alarming, signal scaling, signal filtering, signal status calculation, mode control, and simulation.
In Automatic mode, the block's output parameter (OUT) reflects the process variable (PV) value and status. In Manual mode, OUT can be set manually.
To support testing, you can enable simulation. This allows the measurement value and status to be supplied manually or from another block through the SIMULATE_IN input.
SIMULATE_IN is the simulated value from another block that is used by the Analog Input function block when simulation is enabled.
OUT is the block output value and status.
The following diagram shows the internal components of the Analog Input function block. The parameters may vary slightly for extended blocks.
