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Chapter 8 Communication Functions
8-15
3) Individual writing of device(W(w)SS)
(1) Introduction
This is a function that writes the PLC device memory directly specified in accord with memory data type.
(2) PC request format
Format name Header Station No. Command
Command
type
Number of
blocks
Device
Length
Device Name Data
Tail
Frame
check
Frame (Example)
ENQ H20 W(w) SS H01 H06 %MW100 H00E2
.....
EOT BCC
ASCII
value
H05 H3230 H57(77) H5353 H3031 H3036
H254D5731
3030
H30304
532
H04
1 block(setting can be repeated up to max. 16 blocks)
Item Explanation
BCC
When command is lowercase(r), only one lower byte of the value resulted by adding 1 Byte
each to ASCII values from ENQ to EOT is converted into ASCII and added to BCC.
Number of blocks
This specifies how much of the blocks composed of "[device length][device name]" are in
this request Format. This can be set up to 16. Therefore, the value of [Number of blocks]
must be set between H01(ASCII value:3031)-H10(ASCII value:3030).
Device
length(Name
length of device)
This indicates the number of name's characters that means device, 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).
device
Address to be actually read is entered. 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 %MW100 area is H A, the data Format must be H000A. In data area,
the ASCII value converted from hex data is entered.
Ex.1
If type of data to be currently written is WORD, the data is H1234, ASCII code converted value of this is
"31323334" and this content must be entered in data area. Namely, most significant value must be sent first, least
significant value last.
Remark
1) Device data types of each block must be the same.
2) If data type is Bit, the data to be written is indicated by bytes of hex. Namely, if Bit value is 0, it must be
indicated by H00(3030), and if 1, by H01(3031).