PL4 and frequency scan simulations

[miguelmoreto]

I've made some experiments with frequency scan simulations using ATP and ATPDraw 6.2.
The experiments were not exhaustive but I've noticed some modifications in pl4 file:

The field TMAX now is the FMAX (maximum frequency of the scan). In a similar manner, delta_t becomes delta_f.

The line 0x04 is no longer full of zeros. It will show different content based on the type of simulation output:

• Abs output: the line 0x04 is 00 00 00 00 01 00 00 00 00 00 00 00 00 00 00 00

• Abs/ang output: the line 0x04 is 01 00 00 00 02 00 00 00 00 00 00 00 00 00 00 00 and the number of channels doubled.

• Re/img output: the line 0x04 is 02 00 00 00 02 00 00 00 00 00 00 00 00 00 00 00 with also twice the number of channels.

• All output: the line 0x04 is 03 00 00 00 04 00 00 00 00 00 00 00 00 00 00 00 with four times the number of outputs.

It seems that bytes 0 to 3 represent the type of output and bytes 4 to 7 the number of channels per measured variable.

There are changes in bytes 12 to 15 in line 0x02. They seems to change as the simulation and type of output changes.

There are no changes in the ASCII lines of measurement names, but they are doubled or quadrupled accordingly with the simulation type and output. VT parameter also didn't changed.

I didn’t check the parameter NPD (Number of frequencies per decades in logarithmic scan) yet.

[ldemattos]

Hey @miguelmoreto ,

Thanks for your comments.

On branch issue_#1 I did the first modifications on readPL4 to be able to read PL4 for files with frequency scan records. In these process, your comments were valuable.

On my PL4 files the modified algorithm was already capable of reading frequency scan simulations data successfully. Actually, very little modifications were necessary. I did also updates on the wiki pages to describe the frequency scan header.

Would you mind in test these new branch with your simulations?

PS.: I did not tackle the NPD yet.

Best regards!