Filter
Top Products
15 - 11
MELSEC-QnA
15 FUNCTIONS (FUNCTION VERSION B OR LATER)
15.6 Dedicated Instructions
Transient transmission can be performed to the intelligent device station and local
station using dedicated instructions.
Dedicated instructions also facilitate read/write of data with handshake from/to remote
devices.
The dedicated instructions that can be used from different types of stations are shown
in Table 15.6. Refer to the QnACPU Programming Manual (Special Function Module)
for the detail of each instruction.
Table 15.6 List of available dedicated instructions at different stations
Availability ( : available, : not available)
A
pplicable station Instruction Description
Master station Local station
Standby master
station
CCL
CCLEND
Registers mail box for intelligent device and remote
device instructions
SPCCLR
Issues an interruption instruction to the intelligent
device instruction.
SPCBUSY Reads status of remote station.
Reads data in the buffer memory of the specified
station.
RIRD
Reads device data in the CPU of the specified
station.
Writes data into the buffer memory of the specified
station.
Master station,
local station
RIWT
Writes data into the CPU of the specified station.
RIRD
Reads contents in the buffer memory of the
specified station.
RIWT
Writes data into the buffer memory of the specified
station.
RISEND
Writes data with handshake into the buffer memory
of the specified station.
RIRCV
Reads contents with handshake in the buffer
memory of the specified station.
RIFR
Reads contents in the automatic refresh buffer of
the specified station.
(Random access buffer can be specified.)
Intelligent device
station
RITO
Writes data into the automatic refresh buffer of the
specified station.
(Random access buffer can be specified.)
It can be used with software version J (manufactured in Jan., 1998) or later.
POINT
(1) Execute the dedicated instructions during data link.
If any of them is executed in the offline mode, an error does not occur but the dedicated
instruction is not completed. After changing the offline mode to the online mode, reset the
CPU.
(2) Since the dedicated instructions use the last two bits of RX/RY of the target station as a
handshake signal, do not execute write using the TO instruction, etc. during execution of
any of the dedicated instructions.