LS Industrial Systems GLOFA G7M-DR20U, Руководство пользователя

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Chapter 8. Communication Functions
8-17
4) Continuous writing of the direct variable (W(w)SB)
(1) Introduction
This is a function that directly specifies the PLC device memory and continuously writes data from the specified address
for as long as specified.
(2) Request format
Format
name Header
Station
No.
Command
Command
type
Device
length
Device
name
No. of data Data Tail
Frame
check
Frame
(Ex.)
ENQ H10 W(w) SB H06
%MD1
00
H01
H111
12222 EO
T
BCC
ASCII
value
H05 H3130 H57(77) H5342 H3036
H254D
44
313030
H3031
H313
13131
32323
232
H04
Item Description
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
This indicates the number of device name's characters, which is allowable up to 16 characters. This
value is one of ASCII converted from HEX type,
- If the device name is %MW0, it has 4 characters to be H04.
- If the device name is %QW0.0.0, it has 8 characters to be H08.
Device name
Address to be actually read is entered. This must be ASCII value within 16 characters, and in this
name, digits, upper/lower case, '%' only is allowable to be entered.
No. of data Specifies the no. of data to read continuously from the specified address. The example above writes 1
double word serially from %MW100. Up to 120 data is available for continuous writing.
Frame check
(BCC)
When the command is lowercase(r), only one lower byte of the value resulted by adding 1 byte each
to the ASCII values from ENQ to EOT is converted into ASCII and added to BCC, and then sent.
(3) GM7U main unit response format (ACK response)
Format name Header
Station
No.
Command Command type Tail Frame check
Frame (Ex.) ACK H10 W(w) SB ETX BCC
ASCII value H06 H3130 H57(77) H5342 H03
Item Description
BCC
When the command is lowercase(r), only one lower byte of the value resulted by adding 1 Byte
each to the ASCII values from ACK to ETX is converted into ASCII and added to BCC, and then
sent.