Mitsubishi MELSEC-A Series Reference Manual page 189

7. DATA LINK SETTINGS
(3)
2) Range used by the system
The range used by the system is from the head device number of M
area assigned from each remote I/O station to "number of use points - 1 ".
For example, when three special function modules are installed to remote I/O
station No.2, the range W360 to 362 in the M
shown below is used by the system.
Make sure that the number of link points per station is as follows. (Refer to Section
7.6.1.)
• Remote I/O station...........
POINT
(1) If the M R area used by the system is used incorrectly in a user program,
data cannot be read/written correctly, when the RFRP/RTOP instruction is
executed.
(2) The number of link points can be reduced by mounting modules to a remote
I/O station in groups of input modules, special function modules, and output
modules as shown below. If the installation of I/O modules is changed from (a)
to (b), a reduction of 16 input assignment points and 32 output assignment
points can be achieved.
REMARK
The same concept is used to set the link parameters of a remote I/O system
configured in the MELSECNET
system configured in the MELSECNET mode.
512 bytes or less
(Inputs and outputs are 512 points of X/Y0 to 1FF)
composite mode and that of a remote I/O
7 - 51
R area W360 to W3AF
R