Send Area And Send Data Arrangement - Mitsubishi Electric MELSEC iQ-R Series User Manual

Send area and send data arrangement

This section explains the send area and the send data arrangement for performing data transmission using the nonprocedural
protocol.
Send area
The send area is a memory to write data and the data quantity that are transmitted from the CPU module to a target device via
C24.
The send area is assigned to the address, Un\G1024 to 1535 (CH1 side), Un\G2048H to 2559 (CH2 side) by default.
CH1
Buffer memory
address
Un\G1024
Transmission data count designation area
Un\G1025
Transmission data designation
Un\G1535
(Default)
The position and size of the send area in the buffer memory can be changed with Engineering tool in accordance with the
specifications of the target device and the send data length. (Page 422 PARAMETER SETTING)
Configure the settings as follows:
Navigation window  [Parameter]  [Module Information]  "Module Name"  [Module Parameter]  "Basic Settings"
 "Various control specification"
• Designate the start address for the area to be used as the send area in the user setting area (Un\G1024 to 6911, Un\G9728
to 16383) to "Send buffer memory start address designation".
• Designate the length of the area to be used as the send area in the user setting area (Un\G1024 to 6911, Un\G9728 to
16383) by address count (0001H to 1A00H) to "Send buffer memory size specification".
When changing the position and size of the send area in the buffer memory, if any of the functions below are used
concurrently, make sure not to overlap with the buffer memory addresses assigned for storing send/receive data handled with
the functions.
• MC protocol buffer memory read/write function
• MC protocol on-demand function
• Predefined protocol function (Send/receive data storage area)
• Nonprocedural protocol transmission/receive function
• Bidirectional protocol transmission/receive function
• Send/receive data monitoring function
Set the size of data per data transmission from the target device to C24 to be equal to or smaller than the size of the send
data storage area in the buffer memory.
• (Send data storage area)  (Amount of data in any data portion to be transmitted from C24)
To transmit data whose size is larger than the send data storage area, increase the send area, or divide the send data before
sending.
The position and size of send area can be changed in the buffer memory.
• 'Send buffer memory start address designation' (Un\G162/322)
• 'Send buffer memory length designation' (Un\G163/323)
3 DATA COMMUNICATION USING NONPROCEDURAL PROTOCOL
78
3.2 Transmitting Data to Target Device
The unit of transmission data count(words/bytes) is in accordance with the
word/byte units designation with Engineering tool.
The transmission data count designated with the OUTPUT instruction is written.
The transmission data designated with the OUTPUT instruction is written.