Discussion Forums

FAST Protocol   < Previous   Next >

Re: Identify Frame lenght in FAST UDP packet
Himanshu K / ABC DDLLLL
9 Feb 2012 6:50AM ET

It's working now...

Thanks Janaka for valuable help..:)

> Hi,
>
> In the Case 1,
> Very first bit also have a stop bit.
> So your message length is 113. That contains in a single byte
>
> But in case 2,
> you need to take 2 bytes,
>
> 00000001 10001011
>
> After removing stop bits,
> 0000001 0001011
>
> Then convert that value to decimal
> 00000010001011 = 139
>
> now your message length is 139.
>
>
>
>
> > Hi Janaka
> >
> > Binary feeds received have following value in first four bytes.
> > What will be stop bit here to find message length here ?
> >
> > case 1.
> >
> > Uncompressed binary data received
> >
> > F1                DE                 00                 83
> > 11110001        11011110        00000000        10000011
> >
> >
> >
> > Removing first bit and converting to integer value
> >
> > 1110001                11011110        -                0000011        
> >
> > Integer Value
> >
> > 113                94                                3
> >
> > ************************************************************************
> >
> >
> > Case 2
> >
> > Uncompressed binary data received
> >
> >
> > 01                8B                DE                00
> > 00000001        10001011        11011110        00000000
> >
> >
> > Removing first bit and converting to integer value
> >
> > -                0001011                1011110                -
> >
> > Integer Value
> >
> > -                11                94                -
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > > frame size also a integer value, So you can use integer encoding/ decoding method to resolve the value and you can identify the field termination by stop bit.
> > >
> > >
> > > > Hi
> > > >
> > > > I am receiving UDP packet in following manner
> > > >
> > > > |frame size(1)|msg(1)|frame size2|msg(2)|...|frame size(i)|msg(i)|
> > > > =================================================================
> > > > UDP PACKET N
> > > >
> > > > How to identify frame length so that I can find size of msg(1)...consequently of msg(2)......msg(3)....
> > > >
> > > > Frame size usually the first byte but it can be up to 4 bytes of uncompressed data received.How to identify when it's more than 1 byte?
> > > >
> > > > Thanks
> > > >
> > > > Himanshu

Identify Frame lenght in FAST UDP packet
Himanshu K / ABC DDLLLL   7 Feb 2012 4:56AM ET

Re: Identify Frame lenght in FAST UDP packet
janaka Sooriyaarachchi / MillenniumIT   7 Feb 2012 10:58PM ET

Re: Identify Frame lenght in FAST UDP packet
Himanshu K / ABC DDLLLL   8 Feb 2012 7:55AM ET

Re: Identify Frame lenght in FAST UDP packet
janaka Sooriyaarachchi / MillenniumIT   8 Feb 2012 9:52PM ET

Re: Identify Frame lenght in FAST UDP packet
Himanshu K / ABC DDLLLL   9 Feb 2012 6:50AM ET