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6 EXCHANGING DATA WITH AN EXTERNAL DEVICE
6.3 Exchanging data using the buffer memory automatic update function
When using the buffer memory automatic update function, data is transmitted and
received via the master station automatic update buffer (transmission area) using the
FROM/TO command or CC-Link dedicated command RITO/RIFR.
To use the buffer memory automatic update function, set the mode setting switch to "1"
(buffer memory automatic update function enable), and initialize the automatic update
buffer (refer to section 5.5.1 for details).
POINT
(1) The address for the automatic update buffer differs for the A Series master
module and Q/QnA Series master module as follows.
Refer to section 5.2 for details on changing the banks.
•
A Series master module : Bank 2 M 0H to FFFH
•
Q/QnA Series master module : M 2000H to 2FFFH
(2) When using the RITO/RIFR command, the bank is changed automatically, so it
does not need to be changed by the user.
6.3.1 Transmitting data to an external device
The method for transmitting data to an external device using the buffer memory
automatic update function is explained in this section.
(1) Flow of process
The flow of the process for transmitting data to an external device using the
buffer memory automatic update function is shown below.
R2
RS-232-C
Programmable controller CPU
Master station
Bit device
Word device
Remote
input (RX)
Remote
output (RY)
Remote
input (RX)
Remote
output (RY)
3) Automatic read
Trans-
mission
area
Automatic
update
buffer
(transmis-
sion area)
Random area
4) Data transmission
External
device
2) Transmission
request ON
6) Transmission
request OFF
1) Transmission
data write
5) Transmission normal
/error complete ON
7) Transmission normal
/error complete OFF
Trans-
mission