Mitsubishi Electric MELSEC iQ-RJ71C24-R2 - Page 332

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16 TRANSPARENT CODES AND ADDITIONAL CODES
16.3 Handling Transparent and Additional Codes for Nonprocedural Protocol Data Communication
Ex.
When ASCII-BIN conversion is performed
■Data reception using user frames
• C24 checks the reception of the user frame (start frame and final frame).
• C24 deletes (removes) the additional code designation data from an arbitrary data portion when a transparent code for
receiving is specified.
• C24 calculates the sum check code when a sum check code is designated in a user frame (final frame).
• C24 stores the arbitrary data portion in the receive area on the buffer memory.
When ASCII-BIN conversion is designated, C24 converts it to binary code data and stores in the buffer memory.
• C24 issues a reception data read request to the CPU module when the receive end code/data equivalent to the receive end
data quantity is stored during reception of an arbitrary data portion, or when a user frame (final frame) is received.
■Transmitting data using user frames
• C24 transmits data to be sent (an arbitrary data portion of a transmission message), which is designated by the user frame
or CPU module, in the order specified by the user.
• When ASCII-BIN conversion is designated, C24 converts the data in the applicable range to ASCII code data and transmits
it.
In addition, it adds the additional code data immediately before the transparent code/additional code data when transmitting
the data in the applicable range, and transmits it when a transparent code for sending is specified.
• C24 notifies the CPU module of the transmission normal (abnormal) completion once transmission for the send data
quantity has been completed.
The figure above shows how C24 processes the data to be sent/received when the data sending/receiving function using user
frame, the ASCII-BIN conversion function, and/or the data send/receive function by transparent code designation are enabled
and disabled.
Use this information as a reference to select the method to send/receive data for data communication with a target device.
(BC3AH)
(0212H)
31 H 32 H 30 H 10 H 41 H 42 H 43 H
0
32 H 33 H
(0002H)
(H) (L)
223ABC1
D
L
E
00H , 02H
02H , 12H
BCH , 3AH
C24
Target device
(Communicating in an arbitrary format)
Head data Buffer memory (transmission area/reception area)
Additional
code
Transmission data
count/Receive
data
count
Arbitrary data
Send
Conversion
Transmission
data/
receive data
Delete
Addition
Receive
(The data count is in word units)
Transparent code
(For 41H)
Additional code
(For 10H)
C24
Target device
(Transparent code designation) (Sum check code designation) (ASCII-BIN conversion designation)
No
No No
Buffer memory
Data
transmission
Calculating sum
check code using
user frames
ASCII-BIN
conversion of
transmission
data
Data designated
in the transmission
frame No.
designation area
Adding
additional
code
Yes
Yes
Yes
For Output count designation
No
No
No
Data
reception
Check and
delete user
frames
Calculate and
check
sum check code
using user frames
ASCII-BIN
conversion of
arbitrary data
section
Check reception
complete code
and received
data count
Data stored
in the
reception
area
Delete
additional
code
Yes
Yes Yes
(Arbitrary data section only)