237
High-speed Data Exchanges
Section 8-2
8-2
High-speed Data Exchanges
Example 1
When the ASCII Unit functions as a communications interface, the trigger
from the ASCII Unit enables CPU Unit processing to activate a trigger from
the CPU Unit.
In response to data from a bar code reader, an assembly robot is controlled
via CPU Unit processing.
CPU Unit
ASCII Unit
Writes to shared memory using the PC EPUT command
(ASCII Unit No. 1).
Reads from shared memory using the PC EGET com-
mand (ASCII Unit No. 2).
IORD (#00
@@
) and IOWR (#00
@@
) executed
continuously.
Reads from the
shared memory of
ASCII Unit No. 1
to DM 0000 to DM
0009
Writes to the
shared memory of
ASCII Unit No. 2
from DM 0000 to
DM 0009
Unit No. 1,
10 words
Equals Flag
Unit No. 2,
10 words
IORD
#00
@@
#1010
DM0000
IOWR
#00
@@
DM0000
#2010
DM0000
DM0000
ASCII Unit
CPU Unit
1
Sends an IORD Request Flag when
the bar code reader data is input.
→
Receives the IORD Request Flag,
and receives data via the IORD
(#FD00) instruction.
↓
2
After receiving the interrupt, the ASCII
Unit reads the data written to the
shared memory via the PC EGET
command in the interrupt subroutine,
and then issues commands to the
assembly robot.
←
After processing, writes data to the
ASCII Unit shared memory via the
IOWR (#00
@@
) instruction, then
sends an interrupt to the ASCII Unit
via the IOWR (#CC00) instruction.
Shared
memory
CPU Unit
ASCII Unit
Trigger
Inter-
rupt
Command
Bar code reader
Assembly robot
1.
2.
IORD#FD00
IOWR#00
@@
IOWR#CC00
PC QWRITE@
ON PC GOSUB
PC EGET
Summary of Contents for C200H-ASC11
Page 1: ...C200H ASC11 ASC21 ASC31 ASCII Units Operation Manual Revised June 2000...
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