382
Application Example This example shows a program for using the RS-232C port in the RS-232C
mode
to transmit 10 bytes of data (DM 0100 to DM 0104) to the
computer
, and to
store the data received from the computer in the DM area beginning with
DM 0200.
Before executing the program, the following PC Setup
setting must be
made.
DM 6645: 1000 (RS-232C port in RS-232C mode; standard communications
conditions)
DM 6648: 2000 (No start code; end code CR/LF)
The
default values are assumed
for all other PC Setup settings. From DM 0100
to DM 0104, 3132 is stored in every word. From the computer, execute a pro-
gram to receive C200HS data with the standard communications conditions.
@TXD
DM 0100
#0000
#0010
00101SR 26405
@RXD
DM 0200
#0000
265
SR 26406
DIFU(13) 00101
00100
If SR 26405 (the Transmit Ready Flag) is ON
when IR 00100 turns ON, the ten bytes of data
(DM 0100 to DM 0104) will be transmitted,
left
-
most bytes first.
When SR 26406 (Reception Completed Flag)
goes
ON, the
number of bytes of data specified in
SR 265 will be read from the
C200HS’
s
reception
buffer
and stored in
memory starting at DM 0200,
leftmost bytes first.
The data will be as follows:
“31323132313231323132CR
LF”
8-2-6 One-to-one Link Communications
If
two C200HSs or one C200HS and one CQM1 are linked one-to-one by con
-
necting
them together through their RS-232C ports, they can share common LR
areas.
When two PCs are linked one-to-one, one of them will serve as the mas
-
ter and the other as the slave.
Note The peripheral port cannot be used for 1:1 links.
One-to-one Links A one-to-one link allows two C200HSs (or a CQM1) to share common data in
their
LR areas. As shown in the diagram below
, when data is written into a word
the
LR area of one of the linked Units, it will automatically be written identically
into
the same word of the other Unit.
Each PC has specified words to which it can
write
and specified words that are written to by the other PC. Each can read, but
cannot write, the words written by the other PC.
1
11
Master Slave
Master
area
Slave area
W
ritten automatically
.
W
rite “1”
Master area
Slave area
Write
The
word used by each PC will be as shown in
the following table, according to
the settings for the master, slave, and link words.
DM 6645 setting LR 00 to LR 63 LR 00 to LR 31 LR 00 to LR 15
Master words LR00 to LR31 LR00 to LR15 LR00 to LR07
Slave words LR32 to LR63 LR16 to LR31 LR08 to LR15
Wiring Wire the cable as shown in the diagram below using the connector listed.
Applicable Connectors
The following connectors are applicable. One plug and one hood are included
with the CPU.
Parameters for Host Link and RS-232C Communications
Section 8-2
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