Mitsubishi MELSEC LJ71C24, User Manual

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10 DATA COMMUNICATION USING THE NONPROCEDURAL PROTOCOL
POINT
(1) The position and size of the receive area in the buffer memory can be changed
with the GX Works2 in accordance with the specifications of the external
device and the receive data length. (Refer to Section 7.2)
(a) When changing the position and size of the receive area in the buffer
memory with GX Works2, specify as follows:
1) [Various_Control_Specification] screen "For designation of
reception area" "Receive buffer memory head address designation"
Designate the starting address for the area to be used as the receive
area in the user setting area (address: 400
H
to 1AFF
H
, 2600
H
to
3FFF
H
).
2) [Various_Control_Specification] screen "For designation of
reception area" "Receive buffer memory length designation"
Designate by address the length of the area (0001
H
to 1A00
H
) to be
used as the receive area in the user setting area (address: 400
H
to
1AFF
H
, 2600
H
to 3FFF
H
).
(b) When changing the position and size of the receive area in the buffer
memory, if any of the functions below are used concurrently, make sure
that the addresses of the receive area do not overlap with the buffer
memory addresses assigned for storing transmission/receive data with the
functions.
1) MC protocol buffer memory read/write function
2) MC protocol on-demand function
3) Predefined protocol function (transmission/reception data storage
area)
4) Nonprocedural protocol transmission/receive function
5) Bidirectional protocol transmission/receive function
6) Communication data monitoring function
(2) Set the size of data per data transmission from the external device to the C24
so that it is equal to or smaller than the size of the receive data storage area in
the buffer memory.
(Receive data storage area)
≥
(Size of data in any data section to be sent from
the external device)
To transmit data whose size is larger than the receive data storage area,
increase the receive area, or divide the transmission data before sending.