Active vacuum gauges include both the control unit electronics and the actual sensor. This means that active gauges are a complete, self-contained head and driver electronics in one compact unit. The sensor part generates an electrical magnitude from the measured signal.
These gauges typically require 24 V DC and then provide a 0 - 10 V output related to pressure. The bakeout temperature through electronics is limited to <212°F (<100°C), so as a result, bake-out is only possible to a limited extent with the electronics connected. With the electronics removed they can be baked normally up to 150°C.
Linearized output signal, either analogue or digital, means that there are no transmission errors on the cable. The gauge cables are standardized and there is no influence of the line on the measured pressure value.
The controller is simply a display device, so the power supply comes from the plant. The display of signals is on the central display. Pressure is indicated with an analog measurement or via a digital interface. Digital gauges are (actively) independent of a controller and communicate the measured values serially.
It is also important to note that active gauges are sensitive to radiation and magnetic fields.