Chapter 7 XGT Dedicated Protocol
7-6
7.1.5 Detail of instruction
(1) Individual reading of device (R(r)SS
)
(a) Purpose
This is a function that reads PLC device specified in accord with memory data type. Separate
device memory can be read up to 16 at a time.
(b) PC request format
Format
name
Header
Statio
n No.
Comma
nd
Command
type
Number
of
blocks
Device
length
Device name
....
Tail
Frame
check
Ex. of
frame
ENQ H20 R(r) SS H01 H06 %MW100 EOT BCC
ASCII
value
H05
H323
0
H52(72) H5353 H3031 H3036 H254D57313030 H04
Item Description
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. For example, the BCC of the above frame is gotten as below:
H05+H32+H30+H72+H53+H53+H30+H31+H30+H36+H25+H4D+H57+H31+H30+H3
0+H04 = H03A4 Therefore BCC value is A4 (ASCII value : H4134).
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
(Length of
device
name)
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). For
example, if the device name is %MW0, it has 4 characters to be H04 as its length.
If %MW000 characters to be H06.
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, '%' is only allowable to be
entered.
BCC value is low 1byte in the sum of each byte from ENQ to EOT.
In case of making actual frame, 'H' is not attached. Because the number data of frame indicates
hexadecimal.
1 block (settin
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