Chapter 13. Dedicated Cnet communication for GM6
13 - 17
3)
Separate writing of direct variable (WSS)
(1) Introduction
This is a function that directly specifies PLC device memory and writes in accord with data type. Device
memory can be separately written up to 4 memories at a time.
(2) Request format
Format
name
Headr
Statin
No.
Command
Command
type
Number
of
blocks
Variable
length
Variable
name
Data
Tail
Frame
check
Frame
(Ex.)
ENQ
H20
W(w)
SS
H01
H06
%MW100 H00E2
.........
EO
T
BCC
ASCII
value
H05
H3230
H57
(77)
H5354
H3031
H3036
H254D57
313030
H3030
4532
H04
1 blocks(can be repeatedly set up to 4 blocks)
•
BCC : When command is one of lower case(w), only one lower byte of the value resulted by adding 1 Byte
each to ASCII values from ENQ to EOT is converted into ASCII, added to BCC, and sent.
•
Number of blocks : This specifies how much of the blocks composed of '[Variable length][Variable name]'
are in this request format. This can set up to 4 blocks. Therefore, the value of [Number of blocks]
must be H01(ASCII value:3031)-H04(ASCII value:3034).
•
Variable length(Name length of direct variable) : This indicates the number of the name's characters that
registered in direct 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).
•
Direct variable : This is an address of variable to be actually read. This must be ASCII value within 16
characters, and in this name, digits, upper/lower case, '%' and '.' only are allowable to be entered.
•
Data : If the value to be written in %MW100 area is H A, the data format must be H000A. If the value to be
written in %MD100 area is H A, the data format must be H0000000A. In data area, the ASCII value
converted from hex data is entered.
