> to plot time dependencies of the monitored detector parameters, say, voltages or temperatures,
> one needs to convert the coresponging ADC readings into floats.
> 
> One could think of two ways of doing that: 
> 
> - one can perform the ADC-->T or ADC-->V conversion in the MIDAS frontend, 
>   store their [float] values in the data bank, and plot precalculated parameters vs time
> 
> - one can also store in the data bank the ADC readings which typically are short's 
>   and convert them into floats (V's or T's) at the plotting time 
> 
> The first approach doubles the storage space requirements, and I couldn't find the place where 
> one would do the conversion, if stored were the 16-bit ADC readings.
> 
> I'm sure this issue has been thought about, so what is the "recommended MIDAS way" of performing 
> the ADC -> monitored_number conversion when making MIDAS history plots ?

Most experiment go with the second method. The front-end program converts all ADC reading into physicsl 
units, i.e. not only Volt, but even Degrees Centigrade or Tesla or whatever. The slow control part of 
midas then puts these number into /Equipment/<name>/Variables as "float", and the history system picks 
them up from there. This way your history is shown in physical units and not ADC count. Actually the 
recommended slow control framework (check the examples direcotory) does not rely on data banks, but 
puts values directly into the ODB. This is typically done faster, like once per second if a value 
changes, rather than slow control events which are generated maybe once per 10 seconds or once per 
minute. Usually the slow control values are only few compared with trigger data, so a factor of two 
there does not really matter. In the MEG experiment, we have like 400 GB of slow control data per year, 
but 400 TB of trigger data per year.

Best,
Stefan