Details Of The Buffer Memory - Mitsubishi Electric A1SJ71DN91 User Manual

3. SPECIFICATIONS
3.4.2

Details of the buffer memory

This section describes details about the items listed in Table 3.4.
(1) Input Data
(Addresses : 0000
H
Data received from each slave station is saved. The order of the data differs according
to whether the parameters were set by a sequence program or by the configuration
software.
(a) Parameters set by a sequence program
If the parameters were set by a sequence program, the data is saved as a series of
words of a slave station. In the case of double-word data, the data is saved as the
lower word followed by the upper word. If an odd number of byte input modules is
available, one byte of free area must be inserted in order to arrange the data as a
series of words.
A bit input module and a byte input module are handled equally.
See the example below.
<Example>
Station 1 - Byte input modules = 3
Word input modules = 2
Double-word input modules = 2
Station 2 - Byte input modules = 1
Station 3 - Byte input modules = 1
Buffer memory
Word input module
Double-word input module
Byte input module
to 007F /0 to 127)
H
address
Byte module
0000
H
No. 2
0001 Free
H
0002 Word module No. 1
H
0003 Word module No. 2
H
Double-word module No. 1,
0004
H
lower word
Double-word module No. 1,
0005
H
upper word
Double-word module No. 2,
0006
H
lower word
Double-word module No. 2,
0007
H
upper word
0008
H
0009
H
: numeric data represented by bits 9 to 16
: numeric data represented by bits 17 to- 32
: numeric data represented by ON/OFF data or
bits 1 to 8
−
3 9
MELSEC-A
With an odd number of
byte input modules, insert
Byte module
one byte of free area.
No. 1
Byte module
No. 3
Station 1 input data
Byte module
Station 2 input data
No. 1
Byte module
Station 3 input data
No. 1