PMA Digital 380 User Manual

Differentiator with adjustable time constant t and gain P1.
Formula:
[]
{}
yt
t
tT
yt T P xt xt T
r
rr
() (\ ) ()\ (\ )=
+
⋅+⋅1
y(t) = differentiator output
y(t-T
r
) = differentiator output at last calculating cycle
T
r
= calculating cycle time = 160ms (320ms with resistance input)
t = time constant
x(t) = differentiator input
x(t-T
r
) = differentiator input at last calculating cyle
P1 = gain
The control input sets the output to 0.
(1)If the differentiator shall calculate a change per hour
P
t
min
1
60
1⋅=
[]
is required.
(2)If the differentiator shall calculate a change per minute,
P
t
min
1
1
1⋅=
[]
is required.
Procedure
+
Dependent of the maximum rate of change and of the required filter
effect, time constant t must be selected.
+
Use t to calculate the required gain P1 Ä (1) , (2).
Scal:
yaxb=+
(a --> A ; b --> P1)
FiLt Filterfunction t: Filter time constant ; b_F:Filterbandwidth
Parameter Point determines the number of digits behind the decimal point
in the display (0...4). , when the output value of Func2 is displayed (normal
condition) see also p. 9 , switch Ct-di.
12
9499-040-24701
LEAd
SCAl
dISPL
---.--

PMA Digital 380 Specifications

General

Brand	PMA
Model	Digital 380
Category	Measuring Instruments
Language	English