Omron C200H-ASC11, Manual, Page: 86 / 301

77
Details of the Data Exchange Methods
Section 6-3
PC WRITE When the ASCII Unit receives an ON Read Bit from the CPU Unit, it writes the
contents of the specified variable to the I/O memory area specified in the allo-
cated I/O.
1,2,3... 1. Request by PC WRITE command.
2. Read Bit turned ON via the OUT command in the ladder diagram
3. During the I/O refresh period, the Read Bit (n bit 02) from the CPU Unit to
the ASCII Unit turns ON.
4. At the next I/O refresh period, the ASCII Unit writes data (ASCII Busy Flag
goes ON).
5. When the ASCII Busy Flag changes to ON, the Read Bit turned OFF in the
ladder diagram.
6. Once the PC WRITE command data transfer has been completed, the
ASCII Busy Flag is turned OFF by the system.
The following example is for a C200HX/HG/HE PC.
CPU Unit
#
❍❍❍❍
#
❍❍❍❍
ASCII Busy
Flag
IR n bit 01 (Unit
No. 0: IR 10002)
2.
3. Read Bit (trigger) at I/O
refresh
ASCII Unit
1.
Transfer data area (e.g., DM)
No. of transfer words (e.g., 3)
n + 3: IR 103
n + 4: IR 104
Specified
words
3. Allocated IR words
(at I/O refresh)
First word of write I/O memory at
PC WRITE (e.g., 200)
4. Via PC WRITE command
3 words
255 words max. per
command
At next I/O refresh
ASCII Unit on standby
until here.
20 words max. per cycle (except as shown below)
127 words max. per cycle (C200HX/HG/HE or CS1-series
PC and number of transfer bytes
per cycle is 127 words at DM m +
4 in the Setup Area)
IR n+5
bit 00