Badger Meter SRD/SRI Valve Positioners - Manual (Page 43)

Split Range
Split-Range, PV_Scale Splitting
Figure 38: Split range
Split Range is useful if an additional control range is demanded
that cannot be covered by one valve only A valve of smaller
nominal size can be applied overtaking the smallest quantities;
a parallel mounted valve of bigger nominal size takes on the
larger quantities
With conventional positioners, this function is realized through
serial connection of the instruments and allocation of individual
regulating ranges (see drawing) With SRD with analog setpoint
value (version HART or “without communication”), this can be
adjusted with menus 5 5 and 5 6
The other versions of the SRD receive the set value via digital
means; the input signal cannot be split The function can be
realized either in the primary control system, in which setpoint
values are calculated for each valve, or via the variables PV_
SCALE With PV_Scale the digital input setpoint value can be
assigned to the valve span
Example: At low current, only the smaller valve positions; from
approximately 40%, the large valve is added
Page 43
Startup
August 2014 POS-UM-00009-EN-02