Basic Operation - Omron SYSMAC C Series Operation Manual

Data Exchange with CPU Unit
Four-word Operating
Mode
Instructions such as MOV
are used to write to or
read from the allocated
I/O words.
MOV,
etc.
Read/Write Pointer:
I/O words allocated for a
This pointer specifies RAM
Special I/O Unit
addresses in the Analog
Output Unit. Write
destination and read
source addresses are
specified in the pointer.
Comparison between Two-word and Four-word Operating Modes
Operating Instructions
mode available
Two-word I/O READ (READ)
operation and I/O WRITE
(WRIT)
Four-word MOV, OUT, and
operation other instructions

9-3-1 Basic Operation

Two-word Operating Mode
1, 2, 3...
154
The MOV, OUT, and other generic instructions are used to read and write RAM
data in the Analog Output Unit through the allocated I/O words. One word is read
or written at a time. Data is exchanged at I/O refresh.
CPU Unit
Data memory, etc.
I/O
refresh
Word n
Write data
Word n+1
Address
Word n+2
Read data
Word n+3
Access to RAM
Each time an
instruction is executed.
High-speed processing
is possible.
At the I/O refresh
1. Use the I/O WRITE instruction, WRIT, to write parameters to the specified
addresses in the Analog Output Unit.
2. After 100 ms (internal processing time required for the Analog Output Unit),
use the WRIT instruction to write conversion data to addresses 02 to 08 in
the Analog Output Unit.
Write parameters
After 100 ms
Write conversion data
Note Specify a value greater than 1 as the number of words transferred in the WRIT
instruction.
Analog Output Unit
Address
Read
Write
Data exchange Word access
63 words max. Direct access
One word at a Indirect access
time (via the allocated
I/O words)
Using WRIT instruction (see
note)
Timer instruction is used.
Using WRIT instruction (see
note)
Section 9-3
RAM Data:
Addresses 01 to 08 contain the data
for 8 output points. Other addresses
contain the scaling upper and lower
limits, upper and lower limits,
biary/BCD mode settings, and other
parameters/flags.
8 analog output points
Read/write process is performed
for RAM address indicated by the
Read/Write Pointer. One word is
read or written at a time.
Read/write process is performed
through handshaking with the
Read/Write Request Bit, PC Write
Completed Bit, and PC Read
Completed Bit.
Restrictions
Cannot be used
for Units on
SYSMAC BUS
Slave Racks.
Can be used for
Units on SYSMAC
BUS Slave Racks.