|
FAST Protocol
< Previous Next >
Re: swx MDI decoding issue
Rolf Andersson / Pantor Engineering
13 May 2009 3:56AM ET > Rolf,
>
> I am sorry I got confused again. For tag 271, the pmap bit is 0.
> so the default value 0 is used for exponent. Can we say that the
> exponent has a value so that we need to decode mantissa?
> If so, the encoded value is 0x82 for the mantissa. The decoded
> value should be 1 since it is delta operator, Right?
Yes, 0x82 is for the mantissa.
No, the decoded mantissa value is 2.
Why do you think the value should be 1?
> BTW, if the length field of a sequence field is greater than 1,
> does the sequence pmap appear each iteration?
yes, as noted in my mail below
(FAST 1.1 spec section 6.2.5 says: "If any instruction of the group needs to allocate a bit in a presence map, each element is represented as a segment in the transfer encoding." "element" in this context is synonymous with my use of "iteration" in my mail below)
/Rolf
... snip ...
>> Michael,
>>
>> The pmap entry for the length field is located in the _message_
>> level pmap (bit 7 in this case). The sequence level pmap occurs
>> for every iteration (repetition) of the sequence and provides
>> presence info for the fields in the current iteration.
Re: swx MDI decoding issue
Rolf Andersson / Pantor Engineering 13 May 2009 3:56AM ET
|
