Mitsubishi MELSEC Q Series Reference Manual page 127

3 - 67
3 WHEN COMMUNICATING USING THE QnA COMPATIBLE 3E/3C/4C FRAMES OR 4E FRAME
2) Device code
This value identifies the device memory to be read or written.
a) The device codes are shown in the table in (3).
b) When data is communicated in ASCII code
The device code is converted to a 2-digit ASCII code and
sequentially transmitted beginning from the most significant digit.
(Example)
In case of an input relay
The input relay device code "X " is sequentially transmitted
from "X".
The second character " " can be designated a space (code: 20
c) When data is communicated in binary code
The 1-byte value shown in the table in (3) is transmitted.
3) Head device (device)
This value designates the number of the device memory to read data
from or write data to.
When a range of contiguous device memory numbers are designated,
the head number of that device memory range is designated.
The head device number is designated by the data representation
(decimal or hexadecimal) shown in the "Representation" column of the
table shown in (3) according to the objective device memory.
a) When data is communicated in ASCII code
The device number shown in the table is converted to a 6-digit
ASCII code and sequentially transmitted beginning from the most
significant digit.
The "0" column of the most significant digit (in for example
"001234", this refers to "0" of the first two characters) can also be
designated by a space (code: 20
(Example)
In case of internal relay M1234 and link relay B1234
Internal relay M1234 and link relay B1234 become both
"001234" or "
the first "0 "or " ".
b) When data is communicated in binary code
The 3-byte value shown in the table is sequentially transmitted
beginning from the low byte (L: bits 0 to 7).
(Example)
In case of internal relay M1234 and link relay B1234
Internal relay M1234 becomes 0004D2
the order of D2
Link relay B1234 becomes 001234
order of 34
4) Device points
This value designates the number of points to be read or written when
each command is executed. It should be designated within the limits to
the number of points that can be processed per communication given
in the table in (1).
).
H
1234" and are sequentially transmitted from
, 04 , and 00 .
H H H
, 12 , and 00 .
H H H
and is transmitted in
H
and is transmitted in the
H
3 - 67
).
H