These instruments are built to comply with contemporary industrial practices and replace our earlier versions with analog and discrete devices. There are two displays, one for PV input [4-20 mA or 1-5 V] in engineering units and the second for output [4-20 mA] in %. Inputs are 4-20 mA or 1-5 V for HES. Auto and manual modes of operation are possible. User settable features for PV display are decimal point, range, correction factors, square rooting and input open or short. Display of output can be reversed and Manual to Auto ramp time can also be set by the user. Auto to Manual change over is bumpless.