Agilent Technologies 35670A

To calculate the open loop response
1 Measure the close loop response.
2 Press [
Analys
][
DEFINE FUNCTION (F1-F5)
][
DEFINE F1
].
3 Press [
MEAS DATA
][
FREQ RESP 2/1
]
Press [
/
].
Press [
(
].
Press [
CONSTANT (K1-K5)
][
CONSTANT K1
].
Press [
-
].
Press [
MEAS DATA
][
FREQ RESP 2/1
].
4 Press [
ENTER
].
5 Press [
Active Trace
][
AB
].
Press [
Meas Data
][
MORE CHOICES
][
MATH FUNCTIO N
].
Press [
F1
].
6 Press [
Scale
][
AUTOSCALE ON OFF
] to highlight ON.
Press [
Active Trace
][
A
].
Press [
Trace Coord
][
PHASE
].
Press [
Scale
][
AUTOSCALE ON OFF
] to highlight ON.
This task uses the Agilent 35670A’s math operations to calculate the closed loop to
open loop transfer function, T/(1-T).
51.2Hz 10kHz
A: F1 FRES21/(K1 X:51.2 Hz Y:175.686deg
180
deg
-180
Phase
36
deg
/div
X:51.2 Hz Y:-4.7542dB
B: F1 FRES21/(K1
51.2Hz 10kHz
5
dB
-45
dB
dBMag
5
dB
/div
Trac Coord
[SINE]
A: Phase B: dB Mag
C: dBMag D: dBMag
F1 = FRES21/(K1-FRES21)
F2
F3
F4
F5
K1 = 1.000000 + j 0.000000
K2 = 2.000000 + j 0.000000
K3 = -1.000000 + j 0.000000
K4 = 0.000000 + j 1.000000
K5 = 0.000000 - j 1.000000
Math function register, F1,
contains closed loop to open loop
transfer function (T/(1-T)
Agilent 35670A
Measuring Control Systems Operator's Guide
5-20