Analog Input (generic)

A generic analog input is a channel, not a physical quantity: a value the platform reads from a device without knowing in advance what it measures. The meaning is set when the channel is configured (a signal wired to an I/O module, or a sensor fitted in an interchangeable slot), so the platform records it as Ch0, Ch1, and so on rather than as a named parameter.

Two kinds of device in the sensor catalog expose these channels. The Advantech ADAM-4000 distributed I/O modules turn wired signals into readings: their analog input modules accept voltage, current (4–20 mA and ±20 mA), thermocouple, and RTD signals, and each module's channels map to generic analog inputs, up to eight on the ADAM-4017, 4017+, 4018, 4018+, and 4019+. The RKI Instruments GX-6000 handheld gas monitor and its TSI-branded equivalent, the GM460, report their two smart sensor slots as generic channels Ch1 and Ch2.

An ADAM module connects to a Thiamis gateway over RS-485, read with the ADAM ASCII protocol; each channel's input range is set in the driver, which is where the reading gets its meaning. The GX-6000 and GM460 connect over USB. Their four confined-space gases (combustible gas, oxygen, carbon monoxide, and hydrogen sulfide) are always reported by name. Each of the two smart slots, however, auto-recognizes whichever sensor is fitted (a PID for VOCs, an infrared sensor, or a toxic-gas sensor), so its value depends on that sensor and is ingested as a plain channel.