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Chapter 7 Communication function
7-51
9
Number of blocks: This specifies the number of the blocks composed of [Direct variable name][Direct
variable] in this request format. This can be set up to 4 blocks. Therefore, the value of [Number of blocks] 3
must be H01(ASCII value:3031)-H04(ASCII value:3034).
9
Variable name length : This indicates the number of name’s characters registered in access variable of PLC,
which is allowable up to 16 characters. This value is one of ASCII converted from HEX type, and the range
is from H01(ASCII value:3031) to H10(ASCII value:3130)..
9
Variable name: This is a name of variable to be read actually in ASCII value within 16 characters. Others
than figure, upper/lower cases, ‘%’, ’.’ and ‘_’ are not allowed for variable name. Upper/lower cases are
separately used, but all access variable names of PLC are composed of upper cases. Therfore, use upper
cases only.
Remark
[Note 1]
Device data type of each block must be same. Namely, since data type of variable in each block is
determined by data type of ##, all variables of 4 blocks must be the ones of the data type specified
by ##.
[Note 2]
If ## specifies array data, only 1 block is allowed.
[Note 3]
The number of elements means the number of the elements in array. Namely, if global array variable
XX is specified up to array[0]~[5], the number of elements becomes H06.
2)
Response Format(for PLC ACK response)
A) For command type of non-array
Format
Name
Header
Station
No.
Command
Command
type(##)
Number of
blocks
Number of
data(**)
Data
Tail
Frame
check
Frame
(Ex)
ACK
H10
R(r) H02 H01 H02 H23A0
ETX
BCC
ASCII
value
H06 H3130
H52(72) H3032 H3031 H3032
H3233413
0
Repeated
block
H03
1 block(Max. 4 blocks)