What is difference between Analogue Input & High Level Analogue Input? What type of instrument have both AI & HHLAI type of input?
The term high level analog input could very well be a vendor-dependent marketing term.
A couple of vendors call a high level analog input one with only 0/4-20mA or 0/1-5Vdc inputs. While an analog input could be either a universal analog input (T/C, RTD, or mA) or dedicated current, voltage or resistance inputs: thermocouple, resistance, RTD, mV, strain gauge.