Write Mask Bit - Mitsubishi MELSEC-Q EQ-V680D1 User Manual

6. HOW TO COMMUNICATE WITH ID TAGS

6.2.5 Write mask bit

Mask
bit data
Write
data
Mask bit data
Data before execution
Write data
Data after execution
*Shaded area: Holds the data before execution.
*Area outlined in bold: Writes the write data.
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The Write Mask Bit command sets the mask bit of the data of the number of bytes
specified in the number of processed points specification area (Un\G4, Un\G4004)
from the address specified in the head address specification area (Un\G3, Un\G4003),
and writes the result in the same address of the ID tag.
When "1" is specified in the mask bit, the ID tag data prior to execution are held and the
buffer memory write data are ignored.
When "0" is specified in the mask bit, the ID tag data prior to execution are replaced
with the write data.
The data subject to mask bit and the data to be written are stored in the data storage
area (Un\G100 to Un\G103, Un\G4100 to Un\G4103).
The following indicates the area that stores the mask bit data and write data for each
number of processed bytes.
Table 6.2 Number of Processed Bytes and Data Storage Area
Number of
Channel
Processed Bytes
1 to 2
3 to 4
(1) Example of use
(a) When executing the Write Mask Bit command in the data storage order 0000
(upper -> lower) of the processing specification, for the four bytes from address
0010
H
Buffer memory
Address
b15
Stored data
Un\G100
0F F0
H
55 AA
Un\G101
H
12 34
Un\G102
H
Un\G103
56 78
H
b7 b0 b7
0 0 0 0 1 1 1 1 1
0 0 0 1 0 0 0 1 0
0 0 0 1 0 0 1 0 0
0 0 0 1 0 0 0 1 0
Mask Bit Data
Un\G100
CH1
Un\G4100
CH2
Un\G100 to Un\G101
CH1
Un\G4100 to Un\G4101
CH2
ID tag
b0 b7 Before
execution
11
0010
H
22
0011
H
0012 33
H
44
0013
H
b0 b7
1 1 1 0 0 0 0 0 1 0 1
0 1 0 0 0 1 0 0 0 1 1
0 1 1 0 1 0 0 0 1 0 1
0 1 0 0 1 0 0 0 0 0 1
Address
Un\G102 to Un\G103
Un\G4102 to Un\G4103
b0 b7
0010
H
H
0011
H
H
0012
H H
0013
H
H
b0 b7
0 1 0 1 1 0 1 0 1 0 1
0 0 1 1 0 1 0 0 0 1 0
0 1 1 0 0 1 1 1 1 0 0
0 0 1 1 0 1 0 1 0 0 0
Write Data
Un\G101
Un\G4101
H
ID tag
After b0
execution
11
H
24
H
13
H
50
H
b0
0 0FF0 55AA
H H
0 1122 3344
H H
0 1234 5678
H H
0 1124 1350
H H
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