[Difx-users] {Disarmed} {Disarmed} Support (bug?) of the mark5access library for the long BW data

[Walter Brisken]

Which version of mark5access are you using?  I believe some recent work by 
Jan Wagner may have fixed some issues like this.

-W

On Wed, 6 Jul 2016, Lupin Lin wrote:

> To whom will concern my problem,
>
> Does the mark5access library can correctly be supported to a data with long BW (e.g., 2GHz)?
>
> I put one example (with ~ 4 GBs of 4-sec duration; the frame format = VDIF_8192-8192-1-2) on the google drive:
> https://drive.google.com/file/d/0B1HngVMFCJesemc1Nzdwc3ZaX28/view <https://drive.google.com/file/d/0B1HngVMFCJesemc1Nzdwc3ZaX28/view>
>
> If I put the following descriptions in a c++ program including in ¡§mark5_stream.h¡¨.
>
> cout << "Nominal band width resolved by Mark5access lib. =  " << 0.5*(ms->samprate) << endl;
> cout << "Number of samples per chan in a frame = " << ms->framesamples << endl;
>
> I will get the following result.
>
> Nominal band width resolved by Mark5access lib. =  -1.07374e+09
> Number of samples per chan in a frame = 32768
>
> Since the data has the BW = 2048 MHz with payload size of 8192 bytes, the correct value for the first line should be 2.048e+09.
> But the second line gives the correct value [8124 * 8 (bits/bytes) * 0.5 (samples/bits)].
> Is this a specific bug in the current mark5access library?
>
> Sincerely,
> --
> Lupin Chun-Che Lin
> Supporting Scientist of GLT (GreenLand Telescope) project
> in Institute of Astronomy and Astrophysics, Academia Sinica,
> 14F of Astronomy-Mathematics Building (Rm: 1405),
> National Taiwan University.
> No.1, Sec. 4, Roosevelt Rd, Taipei 10617, Taiwan.
> Tel: +886-2-2366-5464
> Fax: +886-2-2367-7849
>
>
>
>