4Links Diagnostic SpaceWire Interface DSI-RG408, Руководство пользователя

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Diagnostic SpaceWire Interface
EtherSpaceLink family User Manual
17. 6 . 2 9.
EtherSpaceLink_extract_timetag()
S ynops i s
double EtherSpaceLink_extract_timetag ( EtherSpaceLink DSI_unit,
void * buffer
)
D esc ri pt i on
EtherSpaceLink_extract_timetag()
ext
r ac
t
s
t
h
e t
i
me
-
t
a g f r
om t
h
e
s
u
pp
l
i
e
d pack
et
a
n
d
c onve r t s i t f r om i t s i nte r n a l r e p r e s ent a t i on a s a n i nte g e r mult i p le o f a b a s e t i me ( 1 00 n s ) to a r e a l
(
d
ouble) numbe
r r
e
p r
e
s
ent
i
n
g
t
h
e t
i
me
i
n
s
e
c
on
ds w i
t
h a r
e
s
olut
i
on o
f
t
h
e b
a s
e t
i
me.
N ote : t i me - t a gs a r e ext r ac te d b y t h is f un c t i on f r om bu ff e rs r etu r ne d w i t h t h e
EtherSpaceLink_EXTN
te
r
m
i
n
a
to
r a
n
d i
n
wh i ch
t
h
e
f irs
t b
y
te
is
t
h
e v
a
lue
EtherSpaceLink_TimeTag & 0xFF
.
I nput p ara mete r s
DSI_unit
t h e ha n d le r etu r ne d b y a s u cc e ss f ul
EtherSpaceLink_open()
c omm a n d .
buffer
a
n
a r
e
a c
ont
a i
n
i
n
g a c
ont
r
ol
pack
et
, s
u
ch a s
t
ha
t
r
etu
r
ne
d
b
y
EtherSpaceLink_get_control_packet()
.
Retu r ns
double
t
h
e v
a
lue o
f
t
h
e t i me
-
t
a
g i n t
h
e
pack
et.
E xa mple
bytes_received = EtherSpaceLink_read_packet_full
( DSI_unit, rxbuf, sizeof(rxbuf),
&terminator,
EtherSpaceLink_RETURN_EXTENSION_DATA
);
if (terminator == EtherSpaceLink_EXTN)
{
int extension_value = (int)rxbuf[0] & 255 | 256;
if (extension_value == EtherSpaceLink_TimeTag)
{
printf ("Time-Tag received: %.10fs0,
EtherSpaceLink_extract_timetag ( DSI_unit, rxbuf ) );
}
}
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