Category : Science and Education
Archive   : EEPUB07.ZIP
Filename : STEPS.DOC
control programs. I have included a data file of a -9db/Octave
loop filter, normalized to unity gain at 1 rad/sec.
For a sample run, follow the steps below.
1) Engage CAPS LOCK.
2) Type PHASLOK.
3) When the menu appears type A.
4) At the prompt, type OPNLOOP.DAT. These are the frequency
variables of a -9db/Octave loop filter normalized to unity gain
at 1 rad/sec.
5) When the menu reappears, type C. You will see the system
poles and zeroes.
6) Type N to edit prompts.
7) Type E.
8) Type .1# at the loop gain prompt.
9) Type N at the plot prompt.
10) Type .1# at the start frequency prompt.
11) Type 2.0# at the number of decades prompt.
12) Type .1# at the decade increment prompt.
13) A tabulation of the open and closed loop gain and phase
will appear. This display is usefull to adjust the loop gain for
minimum open loop phase at the unity gain crossover frequency.
14) Make a note of the closed loop ,-3dB frequency. A
frequency that gives anything more than -3dB is adequate.
15) Type N to the new gain prompt.
16) When the menu reappears, type F.
17) Type .1# at the loop gain prompt.
18) Type the appropriate -3dB frequency earlier noted.
19) The loop noise bandwidth will appear. This is useful for
determining total carrier phase deviation.
20) Type N at the new gain prompt.
21) When the menu reappears, type G.
22) Type .1# at the loop gain prompt.
23) The transfer function, F(s) will be displayed as the
ratio of two polynomials.
24) Press any key.
25) When the main menu reappears, type C.
26) You will now see the closed loop frequency variable.
Note that the closed loop zeroes are the same as the open
loop zeroes.
27) Type N at the edit prompt.
28) When the menu reappears type H.
29) The impulse response h (t) will be tabulated.
30) Press any key.
31) Type 0 for start time.
32) Type 25 for stop time.
33) When the annotation prompt appears type N.
34) When the line type prompt appears type 1.
34) Type N at the min/max prompts.
36) Type 0 at the screen oplot prompt.
37) The loop impulse response will be displayed.
38) Press any key.
39) When the menu reappears, type C.
40) Type N at the edit zeroes prompt.
41) Type Y at the edit poles prompt.
42) Type A at the edit options prompt.
43) Type 1 at the how many? Prompt.
44) Type 0 for the real part prompt.
Type 0 for the imaginary part prompt.
The frequency variable list now contains the step
response spectral function, namely, a pole at the
origin.
45) When the menu reappears, type C to inspect the new
frequency variable list.
46) Type N at the edit prompt.
47) Type H.
48) The step response, h(t), will be tabulated.
49) Press any key.
50) Type 0 at the start time prompt.
51) Type 25 at the stop time prompt.
52) Type N at the annotation prompt.
53) Type 1 at the line type prompt.
54) Type N at the min/max prompts.
55) Type 0 for the screen plot.
56) The loop step response will be displayed.
This completes a simplified "run through" of the program.
The programs IFTLOOP, and SMPLOOP, are similar in operation,
but very different in the transient response algorithm. The
first thing you will notice is that the time response takes
longer to compute. This is because they compute 1024 open loop
gain and phase points, subsequently 1024 closed loop gain and
phase points, and then performs a 1024 point inverse Fourier
transform.
The step response is the numerical integration of the
impulse response.
You will notice there is a zero response delay prior to the
beginning of the time response. This delay is generated by a
linear phase generator used for normalization purpose.
In using these programs you should always run the impulse
response first, making sure it has settled completely to zero at
the end of the time base chosen. This ensures the correct
calculation of the step response.
SMPLOOP includes the sinc x characteristics of a sampling
phase detector, and also includes the excess loop pole generated
by non-ideal sampling. HP has an excellent application note on
sampling phase detectors.
Very nice! Thank you for this wonderful archive. I wonder why I found it only now. Long live the BBS file archives!
This is so awesome! 😀 I’d be cool if you could download an entire archive of this at once, though.
But one thing that puzzles me is the “mtswslnkmcjklsdlsbdmMICROSOFT” string. There is an article about it here. It is definitely worth a read: http://www.os2museum.com/wp/mtswslnk/