4Links EtherSpaceLink Series, Руководство пользователя

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EtherSpaceLink-RG408
EtherSpaceLink family User Manual
14. 6 .19.
EtherSpaceLink_link_connected()
S ynops i s
int EtherSpaceLink_link_connected ( EtherSpaceLink ESL_unit
)
D esc ri pt i on
EtherSpaceLink_link_connected()
dete r m i nes w h et h e r t h e S p ac e W ir e l i n k i s c u rr ent ly
c o
nne
c
ted ( i .e.
w h
et
h
e r t
h
e S
p ac
e
W
ir e st
a
te m
ach
i ne i s i n t
h
e R
u
n st
a
te ) .
I nput p ara mete r s
ESL_unit
t
h
e
ha
nd
l
e r et
u
r ned b
y a
s
u cc
ess
f ul
EtherSpaceLink_open()
c o
mm
a
nd.
Retu r ns
+1 Th e l i n k i s c o nne c ted
0
Th
e
l
i n
k
i s n
o
t
c o
nne
c
ted
-
1
A
n e rr
o
r
o cc u
rr ed
Note
EtherSpaceLink_link_connected()
sends a st a t u s r e q u est t o t h e E t h e rS p ac eL i n k u n i t a nd
t
h
en r e
a
ds
f
r
o
m t
h
e
TC P/
I
P c o
nne
c
t i
o
n
u
nt i
l
i t r e
c
e iv es
a
s
u cc
ess
f ul
r es
po
nse. I
f
t
h
e
u
n i t
u
nde r test
g ene r a tes a s y n ch r o n ou s t r aff i c w h i l e t h i s poll i n g t a k es pl ac e , t ha t S p ac e W ir e t r aff i c m ig h t be
d i s
ca
r ded.
EtherSpaceLink_link_connected()
r et u r ns a r es ul t c o de o f - 1 i f a n y S p ac e W ir e d a t a i s lo st.
S ee se
c
t i
o
n 1
4
.
5
.3 , “
A
s
y
n
ch
r
o
n
ou
s Iss
u
es d
u
ri n g S t
a
t
u
s
Poll
i n g
”
,
E xa mple
EtherSpaceLink ESL_unit;
// Open a TCP/IP link to the ESL unit
ESL_unit = EtherSpaceLink_open ( "192.168.3.40" );
// Set up Link 1
EtherSpaceLink_set_active_link ( ESL_unit, 1 );
EtherSpaceLink_set_mode ( ESL_unit, EtherSpaceLink_LINK_mode_normal );
// Wait for a connection
while ( EtherSpaceLink_link_connected ( ESL_unit ) == 0 )
{ usleep ( 5000 );
}
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