1.1 Outline
1-3
!% *! !&)* &$'+*( *(%)$"*) &$$% ($ *! *(%)1
$"*) ()'&%) ($ *!* &(()'&%) *& *! &$$% ($ )"% #
()'&%) ($ ") (*+(% &( ! &$$% ($ ! &##&-"% "1
($ )!&-) *! &'(*"&% & *! &$$% % ()'&%) ($)
Command frame
Command frame
Response frame
Host computer
H8GN
##&- -"* *"$ & * #)* $) +%*"# *! %.* &$$% ") )%* *( *!
!&)* &$'+*( (",) ()'&%) (&$ *!
&$$+%"*"&%) -"*! *! !&)* &$'+*( ( ((" &+* *!(&+ ! )*%1
( 1 "%*(
•
1 &%%*"&%) % &( $."$+$ & %"*) "%#+"%
*! !&)* &$'+*( % &%%* "% &%1*&1 )/)*$)
•
! *&*# # #% *! ") $ $.
•
) )!"# *-")*1'"( # &( #( ( &( -"("% *!
8
7
H8GN
RSĆ485
Pin No. Abbr
8
7
Host computer
RSĆ485
Abbr
FG
-
+
SG
Shielded cable
A(-)
B(+)
6.8V
Terminator
120
Ω
(1/2W)
Shielded cable
H8GN
end node
RSĆ485
Pin No. Abbr
A(-)
B(+)
Use a terminator of resistance
120
Ω
= (1/2W).
Communications transceiver
TX
RX
A<B: [1] mark
A>B: [0] space
Both ends of the transmission line
(including the host computer) must be
specified (by setting terminator ON) as
the end node. The total resistance of
the terminators must be at least 54
Ω
.
*! *! &$$+%"*"&%) )'""*"&%) & *! % *! !&)* &$1
'+*( &%1*&1 )/)*$ ") "% +) )+( *!* *! &$$+%"*"&%)
)'""*"&%) & ## ,") "% *! )/)*$ .'* "%","+# +%"* %+$()
( *! )$
JTransmission
procedure
JInterface
JWiring
