26
M5
Hold parameter
Parameter M5, P, t, CtI etc. are only for AI MPt control, and have no effect to
on-off control.
M5 is defined as measurement variation after output is changed by 5% (0.5mA if
OP1=1) and when controlled process is basically stabilized. "5" indicates that output
variation is 5 (5% or 0.5mA). Generally M5 parameter of the same system will
changes with measurement value, and so M5 parameter should be configured with
process value around operating point.
Take temperature control of electric furnace as an example, the operating point is
700
℃
. To find out optimum M5 parameter, assuming that when out remains 50%, the
temperature of electric furnace will finally be stabilized at 700
℃
, and when output
changes to 55%, the temperature will final be at 750.
Then M5 (optimum parameter)=750-700=50
℃
. M5 parameter mainly
determines the degree of integral function, similar as integral time of PID control. The
smaller M5 parameter is, the greater integral function is; where the larger M5
parameter is, the smaller integral function is (integral time is increased). But if M=0,
then integral function an artificial intelligence control function will be removed and the
instrument is turned to be an PD adjustment that used as a secondary controller
during cascade control.
0
～
9999
units or
0
～
999.9
℃