swx MDI decoding issue

[dophinnelson_x]

Imported from previous forum

[dophinnelson_x]

Hi All,

I am developing swx feed handler and I have an issue related to decode the FAST data from MDI.

msg:

0000005ah: 00 C6 76 C0 E4 53 57 58 47 52 4F 55 50 2D 4D 44 ;
0000006ah: 49 2E 4D 30 B1 4E 92 32 30 30 38 30 36 32 33 2D ;
0000007ah: 30 33 3A 35 30 3A 32 33 2E 36 31 B1 81 43 48 30 ;
0000008ah: 30 30 34 36 32 36 33 30 B2 81 7B C0 CA 80 80 41 ;
0000009ah: 42 51 B5 80 80 80 80 81 ;

I try to decode it manually.

block size = 00 C6
PMAP = 76 C0 (01110110 11000000)
TID = E4(100)
49 = 53 57 58 47 52 4F 55 50 2D 4D 44 49 2E 4D 30 B1
34 = 4E 92
33 = 32 30 30 38 30 36 32 33 2D 30 33 3A 35 30 3A 32 33 2E 36 31 B1

1021 = 81
48 = 43 48 30 30 30 34 36 32 36 33 30 B2
268 = 81
7B C0 <— ?
269 = CA ?
270 = 80
271 = 80
336 = 41 42 51 B5
346 = 80
6566 = 80
1023 = 80
6567 = 80
83 = 81

I found 7B C0 is appeared between tag 268 and 269. However, I don’t know what it is about. Also I think there is something wrong with the PMAP. e.g the last tag 83, I think the PMAP should be set for this tag.

Thanks in advance
Michael

[rolfandersson58_x]

Michael,

I don’t have the swx spec in front of me, but the “unknown” entity between tags 268 and 269 is probably a pmap for the repeating group.

If you refer to the swx spec you will likely find at least 8 fields in the repeating group with an operator that requires a pmap entry.

(popcnt (7B C0) = 7 and field #5 seems to be defaulted.)

/Rolf

Hi All,

I am developing swx feed handler and I have an issue related to decode
the FAST data from MDI.

msg:

0000005ah: 00 C6 76 C0 E4 53 57 58 47 52 4F 55 50 2D 4D 44 ; 0000006ah:
49 2E 4D 30 B1 4E 92 32 30 30 38 30 36 32 33 2D ; 0000007ah: 30 33 3A 35
30 3A 32 33 2E 36 31 B1 81 43 48 30 ; 0000008ah: 30 30 34 36 32 36 33 30
B2 81 7B C0 CA 80 80 41 ; 0000009ah: 42 51 B5 80 80 80 80 81 ;

I try to decode it manually.

block size = 00 C6 PMAP = 76 C0 (01110110 11000000) TID = E4(100) 49 =
53 57 58 47 52 4F 55 50 2D 4D 44 49 2E 4D 30 B1 34 = 4E 92 33 = 32 30 30
38 30 36 32 33 2D 30 33 3A 35 30 3A 32 33 2E 36 31 B1

1021 = 81 48 = 43 48 30 30 30 34 36 32 36 33 30 B2 268 = 81 7B C0 <— ?
269 = CA ? 270 = 80 271 = 80 336 = 41 42 51 B5 346 = 80 6566 = 80 1023 =
80 6567 = 80 83 = 81

I found 7B C0 is appeared between tag 268 and 269. However, I don’t know
what it is about. Also I think there is something wrong with the PMAP.
e.g the last tag 83, I think the PMAP should be set for this tag.

Thanks in advance Michael

[dophinnelson_x]

Rolf,

I want to know if the first bit of PMAP for sequence field indicate the presence of length field or not. Is there related information in the spec?

Thanks
Michael

Michael,

I don’t have the swx spec in front of me, but the “unknown” entity
between tags 268 and 269 is probably a pmap for the repeating group.

If you refer to the swx spec you will likely find at least 8 fields in
the repeating group with an operator that requires a pmap entry.

(popcnt (7B C0) = 7 and field #5 seems to be defaulted.)

/Rolf

Hi All,

I am developing swx feed handler and I have an issue related to decode
the FAST data from MDI.

msg:

0000005ah: 00 C6 76 C0 E4 53 57 58 47 52 4F 55 50 2D 4D 44 ;
0000006ah: 49 2E 4D 30 B1 4E 92 32 30 30 38 30 36 32 33 2D ;
0000007ah: 30 33 3A 35 30 3A 32 33 2E 36 31 B1 81 43 48 30 ;
0000008ah: 30 30 34 36 32 36 33 30 B2 81 7B C0 CA 80 80 41 ;
0000009ah: 42 51 B5 80 80 80 80 81 ;

I try to decode it manually.

block size = 00 C6 PMAP = 76 C0 (01110110 11000000) TID = E4(100) 49 =
53 57 58 47 52 4F 55 50 2D 4D 44 49 2E 4D 30 B1 34 = 4E 92 33 = 32 30
30 38 30 36 32 33 2D 30 33 3A 35 30 3A 32 33 2E 36 31 B1

1021 = 81 48 = 43 48 30 30 30 34 36 32 36 33 30 B2 268 = 81 7B C0 <—
? 269 = CA ? 270 = 80 271 = 80 336 = 41 42 51 B5 346 = 80 6566 = 80
1023 = 80 6567 = 80 83 = 81

I found 7B C0 is appeared between tag 268 and 269. However, I don’t
know what it is about. Also I think there is something wrong with
the PMAP.
e.g the last tag 83, I think the PMAP should be set for this tag.

Thanks in advance Michael

[rolfandersson58_x]

Michael,

the length field occupies a bit in the message pmap if there is an operator specified for the length field of the sequence.

I don’t have the FAST spec in front of me but IIRC section 6.2.5 contains info about sequences.

I can check more closely if you send me the template you are using.

/Rolf

Rolf,

I want to know if the first bit of PMAP for sequence field indicate
the presence of length field or not. Is there related information
in the spec?

Thanks Michael

[dophinnelson_x]

Rolf,

The previous message can be decoded successfully after you told me the sequence field PMAP. However, I have another messege that I fail to decode it

msg (block size field is omitted):

F7 01 C8 53 57 58 47 52 4F 55 50 2D 4D 44 49 2E
4D 30 B1 52 D0 32 30 30 38 30 36 32 33 2D 30 33
3A 35 35 3A 30 31 2E 37 39 B9 81 81 1B B0 43 48
30 30 30 33 36 37 31 34 34 B0 80 82 30 33 3A 34
35 3A 30 30 2E 30 30 B3 41 42 51 B5 81 FF 80 80
40 B0 02 AC 32 30 30 38 30 36 32 33 2D 30 33 3A
34 35 3A 30 30 2E 30 30 B3 82 C5 01 C8 38 30 B0
82 14 88 39 37 37 31 39 B3 82 80 81 81 81 A0 B1
FF 81 81 C0 02 AC C1 01 C8 81 34 88 B0 36 32 32
37 36 31 B2 81 98 81 81 81 C0 02 AC C0 01 C8 14
88 37 31 38 36 39 38 B1 82 E8 81 81 81 C0 02 AC
C5 01 C8 B1 82 18 88 31 30 35 37 30 37 35 B9 81
03 CB AF 81 81 81 A0 B1 A0 A5 81 81 81 81 18 88
4C 49 30 30 31 30 37 33 37 32 31 B6 82 7C B0 C4
81 81 81 85 B4 82 38 88 B0 43 48 30 30 30 39 36
39 31 36 30 B8 80 EB 84 81 81 A4 B1 81 FF FD 81
C0 02 AC C0 01 C8 3C 88 B0 31 31 31 37 38 32 35
B5 81 00 F7 82 00 C8 81 81 81 A0 B1 8D 01 B4 81
81 81 81 3C 88 B0 36 39 33 36 30 B0 82 7E FB 81
7E 82 81 81 81 80 18 88 34 38 34 30 36 B7 80 81
81 81 81 C0 02 AC C0 01 C8 14 88 32 33 33 37 34
32 B1 83 FF 81 81 81 C0 02 AC C0 01 C8 3C 88 B1
35 35 34 B0 81 93 82 00 FC 81 81 81 80 3C 88 B0
35 38 33 34 30 B4 80 84 7F BB 82 81 81 C0 02 AC
C0 01 C8 1C 88 32 37 31 36 38 B7 82 FC 83 CA FF

PMAP = F7 (1 1110111)
TID = 01 C8
49 = 53 57 58 47 52 4F 55 50 2D 4D 44 49 2E 4D 30 B1
34 = 52 D0
52 = 32 30 30 38 30 36 32 33 2D 30 33 3A 35 35 3A 30 31 2E 37 39 B9
1021 = 81
268 = 81
Seq PMAP = 1B B0 (0011011 1 0110000)
48 = 43 48 30 30 30 33 36 37 31 34 34 B0
270 = 80
271 = 82 ?

I don’t know how to proceed after tag 270.
Template

2shared.com - free file sharing and storage

Thanks
Michael

Michael,

the length field occupies a bit in the message pmap if there is an
operator specified for the length field of the sequence.

I don’t have the FAST spec in front of me but IIRC section 6.2.5
contains info about sequences.

I can check more closely if you send me the template you are using.

/Rolf

Rolf,

I want to know if the first bit of PMAP for sequence field indicate
the presence of length field or not. Is there related information in
the spec?

Thanks Michael

[rolfandersson58_x]

Michael,

your decoding up to 270 looks alright if I have understood the context correctly.

For 271 (field 5 in the sequence), pmap bit 5 is 0 so the wire representation 0x82 corresponds to:
exponent=-2 (default) mantissa=2 => 2*10^-2?

270=NULL followed by 271=2*10^-2 don’t make much sense though?

I suggest you contact SWX for assistance on this.
Let us know what they say.

Best,
Rolf

Rolf,

The previous message can be decoded successfully after you told me
the sequence field PMAP. However, I have another messege that I fail
to decode it

msg (block size field is omitted):

F7 01 C8 53 57 58 47 52 4F 55 50 2D 4D 44 49 2E 4D 30 B1 52 D0 32 30 30
38 30 36 32 33 2D 30 33 3A 35 35 3A 30 31 2E 37 39 B9 81 81 1B B0 43 48
30 30 30 33 36 37 31 34 34 B0 80 82 30 33 3A 34 35 3A 30 30 2E 30 30 B3
41 42 51 B5 81 FF 80 80 40 B0 02 AC 32 30 30 38 30 36 32 33 2D 30 33 3A
34 35 3A 30 30 2E 30 30 B3 82 C5 01 C8 38 30 B0 82 14 88 39 37 37 31 39
B3 82 80 81 81 81 A0 B1 FF 81 81 C0 02 AC C1 01 C8 81 34 88 B0 36 32 32
37 36 31 B2 81 98 81 81 81 C0 02 AC C0 01 C8 14 88 37 31 38 36 39 38 B1
82 E8 81 81 81 C0 02 AC C5 01 C8 B1 82 18 88 31 30 35 37 30 37 35 B9 81
03 CB AF 81 81 81 A0 B1 A0 A5 81 81 81 81 18 88 4C 49 30 30 31 30 37 33
37 32 31 B6 82 7C B0 C4 81 81 81 85 B4 82 38 88 B0 43 48 30 30 30 39 36
39 31 36 30 B8 80 EB 84 81 81 A4 B1 81 FF FD 81 C0 02 AC C0 01 C8 3C 88
B0 31 31 31 37 38 32 35 B5 81 00 F7 82 00 C8 81 81 81 A0 B1 8D 01 B4 81
81 81 81 3C 88 B0 36 39 33 36 30 B0 82 7E FB 81 7E 82 81 81 81 80 18 88
34 38 34 30 36 B7 80 81 81 81 81 C0 02 AC C0 01 C8 14 88 32 33 33 37 34
32 B1 83 FF 81 81 81 C0 02 AC C0 01 C8 3C 88 B1 35 35 34 B0 81 93 82 00
FC 81 81 81 80 3C 88 B0 35 38 33 34 30 B4 80 84 7F BB 82 81 81 C0 02 AC
C0 01 C8 1C 88 32 37 31 36 38 B7 82 FC 83 CA FF

PMAP = F7 (1 1110111) TID = 01 C8 49 = 53 57 58 47 52 4F 55 50 2D 4D 44
49 2E 4D 30 B1 34 = 52 D0 52 = 32 30 30 38 30 36 32 33 2D 30 33 3A 35 35
3A 30 31 2E 37 39 B9 1021 = 81 268 = 81 Seq PMAP = 1B B0 (0011011 1
0110000) 48 = 43 48 30 30 30 33 36 37 31 34 34 B0 270 = 80 271 = 82 ?

I don’t know how to proceed after tag 270. Template
2shared.com - free file sharing and storage

Thanks Michael

Michael,

the length field occupies a bit in the message pmap if there is an
operator specified for the length field of the sequence.

I don’t have the FAST spec in front of me but IIRC section 6.2.5
contains info about sequences.

I can check more closely if you send me the template you are using.

/Rolf

Rolf,

I want to know if the first bit of PMAP for sequence field indicate
the presence of length field or not. Is there related information in
the spec?

Thanks Michael

[dophinnelson_x]

Rolf,

First, since the length field has an operator, does it occupy the first bit of sequence PMAP? if so, I would like to know why pmap bit 5 is for 271.

For 271, exponent=0(not -2) (copy not default) mantissa=2 => 2*10^0 = 2
the operator of exponent is copy. In this situation, PMAP bit is 0, use the initial value, so exp. = 0, right? If the value is not present in the stream and the state is undefined, then use the intial value. If the value is present and is null value, the field is absent if it is optional i.e. do not use the initial value. Am I right?

BTW, this is the output for the first msg provided by swx
8=FIXT.1.1
35=X
1128=7
49=SWXGROUP-MDI.M01
56=SWXGROUP-MDC
34=10576
97=N
52=20080623-03:55:01.799
1021=1
268=1
279=0
269=0
48=CH0003671440
22=4
271=2
273=03:45:00.003
336=ABQ5
346=1
6566=0
83=1

Michael

Michael,

your decoding up to 270 looks alright if I have understood the context
correctly.

For 271 (field 5 in the sequence), pmap bit 5 is 0 so the wire
representation 0x82 corresponds to: exponent=-2 (default) mantissa=2
=> 2*10^-2?

270=NULL followed by 271=2*10^-2 don’t make much sense though?

I suggest you contact SWX for assistance on this. Let us know
what they say.

Best, Rolf

Rolf,

The previous message can be decoded successfully after you told me the
sequence field PMAP. However, I have another messege that I fail to
decode it

msg (block size field is omitted):

F7 01 C8 53 57 58 47 52 4F 55 50 2D 4D 44 49 2E 4D 30 B1 52 D0 32 30
30 38 30 36 32 33 2D 30 33 3A 35 35 3A 30 31 2E 37 39 B9 81 81 1B B0
43 48 30 30 30 33 36 37 31 34 34 B0 80 82 30 33 3A 34 35 3A 30 30 2E
30 30 B3 41 42 51 B5 81 FF 80 80 40 B0 02 AC 32 30 30 38 30 36 32 33
2D 30 33 3A 34 35 3A 30 30 2E 30 30 B3 82 C5 01 C8 38 30 B0 82 14 88
39 37 37 31 39 B3 82 80 81 81 81 A0 B1 FF 81 81 C0 02 AC C1 01 C8 81
34 88 B0 36 32 32 37 36 31 B2 81 98 81 81 81 C0 02 AC C0 01 C8 14 88
37 31 38 36 39 38 B1 82 E8 81 81 81 C0 02 AC C5 01 C8 B1 82 18 88 31
30 35 37 30 37 35 B9 81 03 CB AF 81 81 81 A0 B1 A0 A5 81 81 81 81 18
88 4C 49 30 30 31 30 37 33 37 32 31 B6 82 7C B0 C4 81 81 81 85 B4 82
38 88 B0 43 48 30 30 30 39 36 39 31 36 30 B8 80 EB 84 81 81 A4 B1 81
FF FD 81 C0 02 AC C0 01 C8 3C 88 B0 31 31 31 37 38 32 35 B5 81 00 F7
82 00 C8 81 81 81 A0 B1 8D 01 B4 81 81 81 81 3C 88 B0 36 39 33 36 30
B0 82 7E FB 81 7E 82 81 81 81 80 18 88 34 38 34 30 36 B7 80 81 81 81
81 C0 02 AC C0 01 C8 14 88 32 33 33 37 34 32 B1 83 FF 81 81 81 C0 02
AC C0 01 C8 3C 88 B1 35 35 34 B0 81 93 82 00 FC 81 81 81 80 3C 88 B0
35 38 33 34 30 B4 80 84 7F BB 82 81 81 C0 02 AC C0 01 C8 1C 88 32 37
31 36 38 B7 82 FC 83 CA FF

PMAP = F7 (1 1110111) TID = 01 C8 49 = 53 57 58 47 52 4F 55 50 2D 4D
44 49 2E 4D 30 B1 34 = 52 D0 52 = 32 30 30 38 30 36 32 33 2D 30 33 3A
35 35 3A 30 31 2E 37 39 B9 1021 = 81 268 = 81 Seq PMAP = 1B B0
(0011011 1 0110000) 48 = 43 48 30 30 30 33 36 37 31 34 34 B0 270 = 80
271 = 82 ?

I don’t know how to proceed after tag 270. Template
2shared.com - free file sharing and storage

Thanks Michael

Michael,

the length field occupies a bit in the message pmap if there is an
operator specified for the length field of the sequence.

I don’t have the FAST spec in front of me but IIRC section 6.2.5
contains info about sequences.

I can check more closely if you send me the template you are using.

/Rolf

Rolf,

I want to know if the first bit of PMAP for sequence field
indicate the presence of length field or not. Is there related
information in the spec?

Thanks Michael

[rolfandersson58_x]

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.

271 should indeed be 2 (exponent=0).

The FIX output would have been helpful earlier. Please provide a more complete description of your problem if you want any more help.

Good luck with your development.

/Rolf

Rolf,

First, since the length field has an operator, does it occupy the
first bit of sequence PMAP? if so, I would like to know why pmap bit 5
is for 271.

For 271, exponent=0(not -2) (copy not default) mantissa=2 => 2*10^0 = 2
the operator of exponent is copy. In this situation, PMAP bit is 0, use
the initial value, so exp. = 0, right? If the value is not present in
the stream and the state is undefined, then use the intial value. If the
value is present and is null value, the field is absent if it is
optional i.e. do not use the initial value. Am I right?

BTW, this is the output for the first msg provided by swx 8=FIXT.1.1
35=X
1128=7
49=SWXGROUP-MDI.M01
56=SWXGROUP-
MDC
34=10576
97=N
52=20080623-
03:55:01.799
1021=1
268=1
279=0
269=0
48=CH0003671440
22=4
271=2
273=03-
:45:00.003
336=ABQ5
346=1
6566=0
83=1

Michael

Michael,

your decoding up to 270 looks alright if I have understood the context
correctly.

For 271 (field 5 in the sequence), pmap bit 5 is 0 so the wire
representation 0x82 corresponds to: exponent=-2 (default) mantissa=2
=> 2*10^-2?

270=NULL followed by 271=2*10^-2 don’t make much sense though?

I suggest you contact SWX for assistance on this. Let us know what
they say.

Best, Rolf

Rolf,

The previous message can be decoded successfully after you told me
the sequence field PMAP. However, I have another messege that I fail
to decode it

msg (block size field is omitted):

F7 01 C8 53 57 58 47 52 4F 55 50 2D 4D 44 49 2E 4D 30 B1 52 D0 32 30
30 38 30 36 32 33 2D 30 33 3A 35 35 3A 30 31 2E 37 39 B9 81 81 1B B0
43 48 30 30 30 33 36 37 31 34 34 B0 80 82 30 33 3A 34 35 3A 30 30 2E
30 30 B3 41 42 51 B5 81 FF 80 80 40 B0 02 AC 32 30 30 38 30 36 32 33
2D 30 33 3A 34 35 3A 30 30 2E 30 30 B3 82 C5 01 C8 38 30 B0 82 14 88
39 37 37 31 39 B3 82 80 81 81 81 A0 B1 FF 81 81 C0 02 AC C1 01 C8 81
34 88 B0 36 32 32 37 36 31 B2 81 98 81 81 81 C0 02 AC C0 01 C8 14 88
37 31 38 36 39 38 B1 82 E8 81 81 81 C0 02 AC C5 01 C8 B1 82 18 88 31
30 35 37 30 37 35 B9 81 03 CB AF 81 81 81 A0 B1 A0 A5 81 81 81 81 18
88 4C 49 30 30 31 30 37 33 37 32 31 B6 82 7C B0 C4 81 81 81 85 B4 82
38 88 B0 43 48 30 30 30 39 36 39 31 36 30 B8 80 EB 84 81 81 A4 B1 81
FF FD 81 C0 02 AC C0 01 C8 3C 88 B0 31 31 31 37 38 32 35 B5 81 00 F7
82 00 C8 81 81 81 A0 B1 8D 01 B4 81 81 81 81 3C 88 B0 36 39 33 36 30
B0 82 7E FB 81 7E 82 81 81 81 80 18 88 34 38 34 30 36 B7 80 81 81 81
81 C0 02 AC C0 01 C8 14 88 32 33 33 37 34 32 B1 83 FF 81 81 81 C0 02
AC C0 01 C8 3C 88 B1 35 35 34 B0 81 93 82 00 FC 81 81 81 80 3C 88 B0
35 38 33 34 30 B4 80 84 7F BB 82 81 81 C0 02 AC C0 01 C8 1C 88 32 37
31 36 38 B7 82 FC 83 CA FF

PMAP = F7 (1 1110111) TID = 01 C8 49 = 53 57 58 47 52 4F 55 50 2D 4D
44 49 2E 4D 30 B1 34 = 52 D0 52 = 32 30 30 38 30 36 32 33 2D 30 33
3A 35 35 3A 30 31 2E 37 39 B9 1021 = 81 268 = 81 Seq PMAP = 1B B0
(0011011 1 0110000) 48 = 43 48 30 30 30 33 36 37 31 34 34 B0 270 =
80 271 = 82 ?

I don’t know how to proceed after tag 270. Template
2shared.com - free file sharing and storage

Thanks Michael

Michael,

the length field occupies a bit in the message pmap if there is an
operator specified for the length field of the sequence.

I don’t have the FAST spec in front of me but IIRC section 6.2.5
contains info about sequences.

I can check more closely if you send me the template you are
using.

/Rolf

Rolf,

I want to know if the first bit of PMAP for sequence field
indicate the presence of length field or not. Is there related
information in the spec?

Thanks Michael

[dophinnelson_x]

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?

BTW, if the length field of a sequence field is greater than 1 , does the sequnce pmap appear each iteration?

Michael

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.

271 should indeed be 2 (exponent=0).

The FIX output would have been helpful earlier. Please provide a more
complete description of your problem if you want any more help.

Good luck with your development.

/Rolf

Rolf,

First, since the length field has an operator, does it occupy the
first bit of sequence PMAP? if so, I would like to know why pmap bit 5
is for 271.

For 271, exponent=0(not -2) (copy not default) mantissa=2 => 2*10^0 =
2 the operator of exponent is copy. In this situation, PMAP bit is 0,
use the initial value, so exp. = 0, right? If the value is not present
in the stream and the state is undefined, then use the intial value.
If the value is present and is null value, the field is absent if it
is optional i.e. do not use the initial value. Am I right?

BTW, this is the output for the first msg provided by swx 8=FIXT.1.1
35=X
1128=7
49=SWXGROUP-MDI.M01
56=SWXGROUP-
MDC
34=10576
97=N
52=20080623-
03:55:01.9
1021=1
268=1
279=0
269=0
48=CH0003671440
22=4
271=2
273=03-
:45:00.003
336=ABQ5
346=1
6566=0
83=1

Michael

Michael,

your decoding up to 270 looks alright if I have understood the
context correctly.

For 271 (field 5 in the sequence), pmap bit 5 is 0 so the wire
representation 0x82 corresponds to: exponent=-2 (default) mantissa=2
=> 2*10^-2?

270=NULL followed by 271=2*10^-2 don’t make much sense though?

I suggest you contact SWX for assistance on this. Let us know what
they say.

Best, Rolf

Rolf,

The previous message can be decoded successfully after you told me
the sequence field PMAP. However, I have another messege that I
fail to decode it

msg (block size field is omitted):

F7 01 C8 53 57 58 47 52 4F 55 50 2D 4D 44 49 2E 4D 30 B1 52 D0 32
30 30 38 30 36 32 33 2D 30 33 3A 35 35 3A 30 31 2E 37 39 B9 81 81
1B B0 43 48 30 30 30 33 36 37 31 34 34 B0 80 82 30 33 3A 34 35 3A
30 30 2E 30 30 B3 41 42 51 B5 81 FF 80 80 40 B0 02 AC 32 30 30 38
30 36 32 33 2D 30 33 3A 34 35 3A 30 30 2E 30 30 B3 82 C5 01 C8 38
30 B0 82 14 88 39 37 37 31 39 B3 82 80 81 81 81 A0 B1 FF 81 81 C0
02 AC C1 01 C8 81 34 88 B0 36 32 32 37 36 31 B2 81 98 81 81 81 C0
02 AC C0 01 C8 14 88 37 31 38 36 39 38 B1 82 E8 81 81 81 C0 02 AC
C5 01 C8 B1 82 18 88 31 30 35 37 30 37 35 B9 81 03 CB AF 81 81 81
A0 B1 A0 A5 81 81 81 81 18 88 4C 49 30 30 31 30 37 33 37 32 31 B6
82 7C B0 C4 81 81 81 85 B4 82 38 88 B0 43 48 30 30 30 39 36 39 31
36 30 B8 80 EB 84 81 81 A4 B1 81 FF FD 81 C0 02 AC C0 01 C8 3C 88
B0 31 31 31 37 38 32 35 B5 81 00 F7 82 00 C8 81 81 81 A0 B1 8D 01
B4 81 81 81 81 3C 88 B0 36 39 33 36 30 B0 82 7E FB 81 7E 82 81 81
81 80 18 88 34 38 34 30 36 B7 80 81 81 81 81 C0 02 AC C0 01 C8 14
88 32 33 33 37 34 32 B1 83 FF 81 81 81 C0 02 AC C0 01 C8 3C 88 B1
35 35 34 B0 81 93 82 00 FC 81 81 81 80 3C 88 B0 35 38 33 34 30 B4
80 84 7F BB 82 81 81 C0 02 AC C0 01 C8 1C 88 32 37 31 36 38 B7 82
FC 83 CA FF

PMAP = F7 (1 1110111) TID = 01 C8 49 = 53 57 58 47 52 4F 55 50 2D
4D 44 49 2E 4D 30 B1 34 = 52 D0 52 = 32 30 30 38 30 36 32 33 2D 30
33 3A 35 35 3A 30 31 2E 37 39 B9 1021 = 81 268 = 81 Seq PMAP = 1B
B0 (0011011 1 0110000) 48 = 43 48 30 30 30 33 36 37 31 34 34 B0
270 = 80 271 = 82 ?

I don’t know how to proceed after tag 270. Template
2shared.com - free file sharing and storage

Thanks Michael

Michael,

the length field occupies a bit in the message pmap if there is
an operator specified for the length field of the sequence.

I don’t have the FAST spec in front of me but IIRC section 6.2.5
contains info about sequences.

I can check more closely if you send me the template you are
using.

/Rolf

Rolf,

I want to know if the first bit of PMAP for sequence field
indicate the presence of length field or not. Is there related
information in the spec?

Thanks Michael

[rolfandersson58_x]

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.

[dophinnelson_x]

Rolf,

Oh I made a mistake that I think mantissa is optional. so the value is decreased by 1.

I want to know how to handle if a field is absent.

Michael

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.

[rolfandersson58_x]

that depends on the field definition.
type? operators? inital value?

please be more specific

/Rolf

Rolf,

Oh I made a mistake that I think mantissa is optional. so the value is
decreased by 1.

I want to know how to handle if a field is absent.

Michael

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.

[dophinnelson_x]

Rolf,

Let’s say there is a field is optional. operator is tail. field type is string and no initial value.
Then when I recevie 0x80 which means is null value, how to proceed?

Here is another case. There is a field is optional and the operator is constant. If the pmap bit is set, should the value appear in the stream or just use the default value?

BTW Can I say that the initial value is used if the field is absent no matter what operator is?

Michael

that depends on the field definition. type? operators? inital value?

please be more specific

/Rolf

Rolf,

Oh I made a mistake that I think mantissa is optional. so the value is
decreased by 1.

I want to know how to handle if a field is absent.

Michael

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.

[rolfandersson58_x]

Michael,

It feels like I’m repeatedly paraphrasing the FAST spec to answer your questions. May I suggest that you read the spec, describe how you interpret it for you use cases and then ask any questions that you might have regarding specific sections of the spec.

/Rolf

Rolf,

Let’s say there is a field is optional. operator is tail. field
type is string and no initial value. Then when I recevie 0x80
which means is null value, how to proceed?

Here is another case. There is a field is optional and the operator
is constant. If the pmap bit is set, should the value appear in the
stream or just use the default value?

BTW Can I say that the initial value is used if the field is absent
no matter what operator is?

Michael

[dophinnelson_x]

Rolf,

Ok. Thank for your help.

Michael

Michael,

It feels like I’m repeatedly paraphrasing the FAST spec to answer your
questions. May I suggest that you read the spec, describe how you
interpret it for you use cases and then ask any questions that you might
have regarding specific sections of the spec.

/Rolf

Rolf,

Let’s say there is a field is optional. operator is tail. field type
is string and no initial value. Then when I recevie 0x80 which means
is null value, how to proceed?

Here is another case. There is a field is optional and the operator is
constant. If the pmap bit is set, should the value appear in the
stream or just use the default value?

BTW Can I say that the initial value is used if the field is absent no
matter what operator is?

Michael