Sharp ER-A490 (serv.man4) Service Manual ▷ View online
( 13 ) Receives text.
Checks the check sum, text lingth, text data, etc.
And goes to (15) if there is no error in them.
Sends NAK if any error occurs.
Checks the check sum, text lingth, text data, etc.
And goes to (15) if there is no error in them.
Sends NAK if any error occurs.
( 15 ) Sends ACK.
( 17 ) Terminates the operation if EOT is received.
( 12 ) Sends text corresponding
to the job code.
to the job code.
( 14 ) Resends text block if NAK is received.
Resends text up to two times,and
performs error handling if NAK is still
received after the second resending
of text block.
Resends text up to two times,and
performs error handling if NAK is still
received after the second resending
of text block.
( 16 ) Sinds the next text if ACK is received,
and sends EOT and terminates the
operation if data transfer is finalized.
and sends EOT and terminates the
operation if data transfer is finalized.
Host
Satellite
EOT
Continued from the
preceding page.
preceding page.
Start code
Text (FDS)
End code
Text (DATA)
Two types of
text block
formats are
available.
text block
formats are
available.
NAK
(When an error
occurs)
occurs)
ACK
Note : For the description of
each data block see section
4 (Text block formats)
each data block see section
4 (Text block formats)
1 – 8
2.
Tran
s
m
issio
n
c
o
n
trol
proc
e
d
u
re
m
a
trix
1) Do
w
n
-l
o
a
d
in
g
matrix f
o
r
th
e h
o
st
STATE
In
itia
l
Afte
r
s
e
n
d
in
g
I
D
E
N
Q
After
sen
d
in
g
text
EVENT
0
1
2
ENQ
—
—
—
ACK
—
S
e
n
ds text an
d
g
o
e
s
t
o
2
.
S
e
n
ds text an
d
g
o
e
s
t
o
2
.
S
e
n
ds EOT an
d
t
h
e
n
g
o
es to 0
.
(Norm
a
l e
n
d)
NAK
—
—
Resen
ds the
text an
d
t
h
e
n
g
o
es to 2
.
If t
h
e
h
ost h
as resen
t t
h
e
t
e
x
t
two t
im
e
s
, i
t s
e
n
d
s
EOT a
n
d
g
o
es to 0
.
(ERROR END)
EOT
—
—
T
h
e
h
ost go
es to 0
.
(ERROR END)
TEXT
—
—
—
T
IME-UP
—
Resen
ds
ID
ENQ
a
n
d
t
h
e
n
g
o
e
s
t
o
1
.
If
t
h
e
h
ost
h
as resen
t
ID ENQ two t
im
es,it s
e
n
d
s
EOT a
n
d
g
o
es to 0
.
(ERRO
R END)
Resen
ds the
text an
d
t
h
e
n
g
o
es to 2
.
If t
h
e
h
o
s
t h
as r
e
s
e
n
t t
h
e
text two
ti
m
es,it sen
ds EOT a
n
d
g
o
es to 0
.
(ERROR END)
KEY ENTRY
S
e
n
d
s
ID ENQ an
d
g
o
e
s
t
o
1
.
—
—
T
im
e
-u
p
:
O
n
e
secon
d
a
fter sen
d
in
g
of ID ENQ.
F
o
u
r
s
e
c
o
n
d
s
a
fter sen
d
in
g
of te
x
t.
1 – 9
2)
Up
-l
o
ad
in
g
mat
ri
x f
or
th
e h
o
s
t
STATE
In
itia
l
Afte
r
s
e
n
d
in
g
I
D
E
N
Q
After
sen
d
in
g
text
EVENT
0
1
2
ENQ
—
—
—
ACK
—
S
e
n
ds
text
an
d
g
o
e
s
t
o
2
.
S
e
n
ds
EOT
an
d
g
o
e
s
t
o
3
.
NAK
—
—
Resen
ds the
text an
d
t
h
e
n
g
o
es to 2
.
If the
h
o
s
t
h
as resen
t t
h
e
text two ti
m
e
s
,
it
g
o
es to 0
.
(ERROR END)
EOT
—
—
T
h
e
h
ost go
es to 0
.
(ERROR END)
TEXT
—
—
—
T
IME-UP
—
Resen
ds
ID
ENQ
a
n
d
t
h
e
n
g
o
e
s
t
o
1
.
If the
h
o
s
t
h
as resen
t ID ENQ
two
t
im
es, it g
o
e
s
t
o
0
.
(ERRO
R END)
Resen
ds the
text an
d
t
h
e
n
g
o
es to 2
.
If the
h
o
s
t
h
as resen
t t
h
e
text two ti
m
e
s
,
it
g
o
es to 0
.
(ERROR END)
KEY ENTRY
S
e
n
d
s
ID ENQ an
d
g
o
e
s
t
o
1
.
—
—
T
im
e
-u
p
:
O
n
e
secon
d
a
fter sen
d
in
g
of ID ENQ.
F
o
u
r
s
e
c
o
n
d
s
a
fter sen
d
in
g
of te
x
t.
STATE
After
sen
d
in
g
EOT
Afte
r
s
e
n
d
in
g
ACK
Afte
r
s
e
n
d
in
g
NAK
EVENT
3
4
5
ENQ
S
e
n
d
s
ACK
a
n
d
g
o
es
to
4
.
After
th
e
h
o
s
t
h
a
s
r
e
c
e
iv
e
d
ENQ,
re
s
e
n
d
s
ACK
a
n
d
g
o
e
s
t
o
4.
After th
e
h
ost ha
s
re
c
e
iv
e
d
T
EXT, ig
n
o
res the
E
N
Q
.
—
ACK
—
—
—
NAK
—
—
—
EOT
T
h
e
h
ost go
es to 0
(ERROR END)
After th
e
h
ost ha
s
re
c
e
iv
e
d
T
EXT, go
es to 0
.
(Norm
a
l e
n
d)
After th
e
h
ost ha
s
re
c
e
iv
e
d
ENQ, g
o
e
s
t
o
0.(ERROR END)
T
h
e
h
ost go
es to 0
.
(ERROR END)
TEXT
—
T
h
e
h
ost che
c
k
s
t
h
e
t
e
x
t b
lo
c
k, i
f t
h
e
b
lo
c
k
is corre
c
t,
t
h
e
h
o
s
t sen
ds ACK an
d
g
o
e
s
t
o
4
.
If it is no
t
c
o
rrect, the
h
o
s
t sen
ds NAK an
d
g
o
e
s
t
o
5
.
If tran
sm
is
s
io
n
c
a
n
n
o
t b
e
co
ntin
u
e
d, t
h
e
h
o
st s
e
n
d
s
E
O
T
a
n
d g
o
e
s
to
0.
T
h
e
h
ost c
h
e
c
k
s
t
h
e
c
h
e
c
k
s
t
h
e
text b
lo
c
k, i
f t
h
e
b
lo
c
k
i
s
c
o
rrect, the
h
o
s
t sen
ds ACK an
d
g
o
e
s
t
o
4
.
If it is no
t
c
o
rrect, the
h
o
s
t sen
ds NAK an
d
g
o
e
s
t
o
5
.
If tran
s
m
is
s
io
n
c
a
n
n
o
t b
e
c
o
n
ti
n
u
e
d
,
th
e
h
ost
sen
ds E
O
T
a
n
d g
o
e
s
to
0.
(ERROR END)
T
IME-UP
Re
s
e
n
d
s
EOT a
n
d
g
o
es to 3
.
If th
e
h
ost ha
s
re
s
e
nt th
e EOT two
t
im
es, it go
es to 0
.
(ERROR END)
The
ho
st g
o
e
s
to
0.
(ERRO
R END)
Tim
e-u
p i
s
7
s
e
co
n
d
s
T
h
e
h
ost go
es to 0
.
(ERROR END)
Tim
e
-up
i
s
7
s
e
co
n
d
s
KEY ENTRY
—
—
—
T
im
e
-u
p
:
Two secon
d
a
fter sen
d
in
g
of EOT.
1 – 10
3) Do
w
n
-l
o
a
d
in
g
matrix f
o
r
th
e sattel
ite
STATE
In
itia
l
Afte
r
s
e
n
d
in
g
A
C
K
Afte
r
s
e
n
d
in
g
NAK
EVENT
0
1
2
ID-ENQ
Sa
tell
ite
c
h
e
c
k
s
the
t
e
rmi
n
a
l No.:If i
t i
s
corre
c
t,
sate
lli
te
sen
ds ACK an
d
g
o
e
s
t
o
1
.
If it i
s
n
ot corre
c
t, Sa
tell
ite i
g
n
ore
s
th
e
ID-ENQ.
Sate
llite
che
c
k
s
t
h
e
t
e
rm
in
a
l No
.:If it i
s
c
o
rrect, s
a
tell
it
e
s
e
n
d
s
ACK a
n
d
g
o
es to 1
.
If it is no
t
c
o
rrect, Sate
llite
i
g
n
o
res the
ID-ENQ
.
—
ACK
—
—
—
NAK
—
—
—
EOT
—
After sate
llite
h
a
s
re
c
e
ived
TEXT, g
o
e
s
to
0.
(Norm
a
l e
n
d)
Befo
re sate
llite
h
a
s
re
c
e
ived
TEXT, ig
n
o
res the
E
O
T
Sate
lli
te g
o
e
s
to
0.
(ERROR END)
TEXT
—
Sate
llite
c
h
e
c
k
s
t
h
e
text b
lo
c
k
, if t
h
e
b
lo
c
k
is
corre
c
t,
Sate
llite
s
e
n
d
s
ACK a
n
d
g
o
es to 1
.
If
i
t i
s
n
o
t
c
o
rrect,
s
a
tell
ite sen
ds NAK an
d
g
o
e
s
to
2.
If
tra
nsm
is
sio
n
c
a
n
n
ot b
e
c
o
n
ti
n
u
e
d
,
sate
llite
sen
d
s
E
O
T
a
n
d g
o
e
s
to
0.
(ERRO
R END)
Sate
lli
te c
h
e
c
k
s
t
h
e
t
e
x
t b
lock
, i
f
th
e
b
lock
is c
o
rrect,
Sate
lli
te sen
ds ACK an
d
g
o
e
s
to
1.
If
i
t i
s
n
o
t
c
o
rrect,
s
a
te
llite
s
e
n
d
s
NAK a
n
d
g
o
es to 2
.
If tran
s
m
is
s
io
n
can
n
o
t
b
e
con
tinu
e
d
,
sate
lli
te s
e
n
d
s
E
O
T
a
n
d g
o
e
s
to
0.
(ERROR END)
T
IME-UP
—
Sate
llite
s
e
n
d
s
EOT, a
n
d
g
o
es to 0
.
(ERRO
R END)
Tim
e-u
p i
s
7
s
e
co
n
d
s
T
h
e
h
ost go
es to 0
.
(ERROR END)
Tim
e
-up
i
s
7
s
e
co
n
d
s
1 – 11
Click on the first or last page to see other ER-A490 (serv.man4) service manuals if exist.