User Guide

Control system parts
161
impose an upper and lower limit on the output. The
TABLE part provides one input and one output.
FTABLE
The FTABLE part is described by a table of frequency
responses in either the magnitude/phase domain (R_I= )
or complex number domain (R_I=YES). The entire table is
read in and converted to magnitude in dB and phase in
degrees.
Interpolation is performed between entries. Magnitude is
interpolated logarithmically; phase is interpolated
linearly. For frequencies outside the table’s range, 0 (zero)
magnitude is used. This characteristic can be used to
impose an upper and lower limit on the output.
The DELAY property increases the group delay of the
frequency table by the specified amount. The delay term
is particularly useful when a frequency table device
generates a non-causality warning message during a
transient analysis. The warning message issues a delay
ROW
n
either an (input frequency, magnitude,
phase) triplet, or an (input frequency, real
part, imaginary part) triplet describing a
complex value; by default, up to five
triplets are allowed where n=1, 2, 3, 4, or
5
DELAY group delay increment; defaults to 0 if
left blank
R_I table type; if left blank, the frequency
table is interpreted in the (input
frequency, magnitude, phase) format; if
defined with any value (such as YES), the
table is interpreted in the (input
frequency, real part, imaginary part)
format
MAGUNITS units for magnitude where the value can
be DB (decibels) or MAG (raw
magnitude); defaults to DB if left blank
PHASEUNITS units for phase where the value can be
DEG (degrees) or RAD (radians); defaults
to DEG if left blank
I
f
more t
h
an
f
ive va
l
ues are require
d
, t
h
e
part can be customized through the part
editor. Insert additional row variables into
the template using the same form as the
first five, and add ROW
n properties as
needed to the list of properties.
Pspug.book Page 161 Wednesday, November 11, 1998 1:14 PM